diff --git a/reactos/include/ddk/rtl.h b/reactos/include/ddk/rtl.h
index edc7c0b061a..e8301c6cda7 100644
--- a/reactos/include/ddk/rtl.h
+++ b/reactos/include/ddk/rtl.h
@@ -1,4 +1,4 @@
-/* $Id: rtl.h,v 1.33 2000/05/09 21:29:44 ekohl Exp $
+/* $Id: rtl.h,v 1.34 2000/05/13 01:44:53 ekohl Exp $
  * 
  */
 
@@ -65,6 +65,28 @@ typedef struct {
 	ULONG		Unknown[11];
 } RTL_HEAP_DEFINITION, *PRTL_HEAP_DEFINITION;
 
+struct _LB_RANGE
+{
+	ULONG dummy;
+};
+
+typedef struct _RTL_NLS_DATA
+{
+	USHORT			CodePage;
+	USHORT			MaxCharacterSize;
+	WCHAR			DefaultCharacter;
+	WCHAR			char1;
+	WCHAR			char2;
+	WCHAR			char3;
+	USHORT			DbcsFlag;
+	struct _LB_RANGE	LeadByteRange[6];
+	USHORT			reserved;
+	PWCHAR			MultiByteToUnicode;
+	PCHAR			UnicodeToMultiByte;
+	ULONG			unknown;
+	PCHAR			DbcsTags;
+} RTL_NLS_DATA, *PRTL_NLS_DATA;
+
 
 /*
  * PURPOSE: Flags for RtlQueryRegistryValues
@@ -425,6 +447,17 @@ RtlCreateUnicodeStringFromAsciiz (
 	IN	PCSZ		Source
 	);
 
+NTSTATUS
+STDCALL
+RtlCustomCPToUnicodeN (
+	PRTL_NLS_DATA	NlsData,
+	PWCHAR		UnicodeString,
+	ULONG		UnicodeSize,
+	PULONG		ResultSize,
+	PCHAR		CustomString,
+	ULONG		CustomSize
+	);
+
 NTSTATUS
 STDCALL
 RtlDeleteRegistryValue (
@@ -1174,6 +1207,17 @@ RtlUnicodeStringToOemString (
 	IN	BOOLEAN		AllocateDestinationString
 	);
 
+NTSTATUS
+STDCALL
+RtlUnicodeToCustomCPN (
+	PRTL_NLS_DATA	NlsData,
+	PCHAR		MbString,
+	ULONG		MbSize,
+	PULONG		ResultSize,
+	PWCHAR		UnicodeString,
+	ULONG		UnicodeSize
+	);
+
 NTSTATUS
 STDCALL
 RtlUnicodeToMultiByteN (
@@ -1246,6 +1290,17 @@ RtlUpcaseUnicodeStringToOemString (
 	IN	BOOLEAN		AllocateDestinationString
 	);
 
+NTSTATUS
+STDCALL
+RtlUpcaseUnicodeToCustomCPN (
+	PRTL_NLS_DATA	NlsData,
+	PCHAR		MbString,
+	ULONG		MbSize,
+	PULONG		ResultSize,
+	PWCHAR		UnicodeString,
+	ULONG		UnicodeSize
+	);
+
 NTSTATUS
 STDCALL
 RtlUpcaseUnicodeToMultiByteN (
diff --git a/reactos/lib/ntdll/def/ntdll.def b/reactos/lib/ntdll/def/ntdll.def
index d81758fdfcd..c6723eed56b 100644
--- a/reactos/lib/ntdll/def/ntdll.def
+++ b/reactos/lib/ntdll/def/ntdll.def
@@ -1,4 +1,4 @@
-; $Id: ntdll.def,v 1.53 2000/04/25 23:22:55 ea Exp $
+; $Id: ntdll.def,v 1.54 2000/05/13 01:48:01 ekohl Exp $
 ;
 ; ReactOS Operating System
 ;
@@ -307,7 +307,7 @@ RtlCreateUnicodeStringFromAsciiz@8
 RtlCreateUserProcess@40
 ;RtlCreateUserSecurityObject
 RtlCreateUserThread@40
-;RtlCustomCPToUnicodeN
+RtlCustomCPToUnicodeN@24
 ;RtlCutoverTimeToSystemTime
 RtlDeNormalizeProcessParams@4
 ;RtlDecompressBuffer
@@ -531,7 +531,7 @@ RtlUnicodeStringToCountedOemString@12
 RtlUnicodeStringToInteger@12
 RtlUnicodeStringToOemSize@4
 RtlUnicodeStringToOemString@12
-;RtlUnicodeToCustomCPN
+RtlUnicodeToCustomCPN@24
 RtlUnicodeToMultiByteN@20
 RtlUnicodeToMultiByteSize@12
 RtlUnicodeToOemN@20
@@ -543,7 +543,7 @@ RtlUpcaseUnicodeString@12
 RtlUpcaseUnicodeStringToAnsiString@12
 RtlUpcaseUnicodeStringToCountedOemString@12
 RtlUpcaseUnicodeStringToOemString@12
-;RtlUpcaseUnicodeToCustomCPN
+RtlUpcaseUnicodeToCustomCPN@24
 RtlUpcaseUnicodeToMultiByteN@20
 RtlUpcaseUnicodeToOemN@20
 RtlUpperChar@4
diff --git a/reactos/lib/ntdll/def/ntdll.edf b/reactos/lib/ntdll/def/ntdll.edf
index 4d96f5b1086..8be8bf6c927 100644
--- a/reactos/lib/ntdll/def/ntdll.edf
+++ b/reactos/lib/ntdll/def/ntdll.edf
@@ -1,4 +1,4 @@
-; $Id: ntdll.edf,v 1.42 2000/04/25 23:22:56 ea Exp $
+; $Id: ntdll.edf,v 1.43 2000/05/13 01:48:01 ekohl Exp $
 ;
 ; ReactOS Operating System
 ;
@@ -272,6 +272,7 @@ RtlCreateUnicodeString=RtlCreateUnicodeString@8
 RtlCreateUnicodeStringFromAsciiz=RtlCreateUnicodeStringFromAsciiz@8
 RtlCreateUserProcess=RtlCreateUserProcess@40
 RtlCreateUserThread=RtlCreateUserThread@40
+RtlCustomCPToUnicodeN=RtlCustomCPToUnicodeN@24
 RtlDeNormalizeProcessParams=RtlDeNormalizeProcessParams@4
 RtlDeleteAce=RtlDeleteAce@8
 RtlDeleteCriticalSection=RtlDeleteCriticalSection@4
@@ -399,6 +400,7 @@ RtlUnicodeStringToCountedOemString=RtlUnicodeStringToCountedOemString@12
 RtlUnicodeStringToInteger=RtlUnicodeStringToInteger@12
 RtlUnicodeStringToOemSize=RtlUnicodeStringToOemSize@4
 RtlUnicodeStringToOemString=RtlUnicodeStringToOemString@12
+RtlUnicodeToCustomCPN=RtlUnicodeToCustomCPN@24
 RtlUnicodeToMultiByteN=RtlUnicodeToMultiByteN@20
 RtlUnicodeToMultiByteSize=RtlUnicodeToMultiByteSize@12
 RtlUnicodeToOemN=RtlUnicodeToOemN@20
@@ -409,6 +411,7 @@ RtlUpcaseUnicodeString=RtlUpcaseUnicodeString@12
 RtlUpcaseUnicodeStringToAnsiString=RtlUpcaseUnicodeStringToAnsiString@12
 RtlUpcaseUnicodeStringToCountedOemString=RtlUpcaseUnicodeStringToCountedOemString@12
 RtlUpcaseUnicodeStringToOemString=RtlUpcaseUnicodeStringToOemString@12
+RtlUpcaseUnicodeToCustomCPN=RtlUpcaseUnicodeToCustomCPN@24
 RtlUpcaseUnicodeToMultiByteN=RtlUpcaseUnicodeToMultiByteN@20
 RtlUpcaseUnicodeToOemN=RtlUpcaseUnicodeToOemN@20
 RtlUpperChar=RtlUpperChar@4
diff --git a/reactos/lib/ntdll/rtl/nls.c b/reactos/lib/ntdll/rtl/nls.c
index 62af79024da..c7eaed0753d 100644
--- a/reactos/lib/ntdll/rtl/nls.c
+++ b/reactos/lib/ntdll/rtl/nls.c
@@ -1,4 +1,4 @@
-/* $Id: nls.c,v 1.2 1999/11/20 21:46:46 ekohl Exp $
+/* $Id: nls.c,v 1.3 2000/05/13 01:47:33 ekohl Exp $
  *
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS kernel
@@ -17,7 +17,8 @@
  *   1) Implement code to initialize the translation tables.
  *   2) Use fixed translation table for translation.
  *   3) Add loading of translation tables (NLS files).
- *   4) Add multi-byte translation code.
+ *   4) Implement unicode upcase and downcase handling.
+ *   5) Add multi-byte translation code.
  */
 
 #include <ddk/ntddk.h>
@@ -42,22 +43,79 @@ NlsAnsiCodePage = 0;
 USHORT
 NlsOemCodePage = 0; /* not exported */
 
-
 #if 0
-WCHAR AnsiToUnicodeTable[256];
-WCHAR OemToUnicodeTable[256];
+PWCHAR NlsAnsiToUnicodeTable = NULL;
+PWCHAR NlsOemToUnicodeTable = NULL;
 
-CHAR UnicodeToAnsiTable [65536];
-CHAR UnicodeToOemTable [65536];
+PCHAR NlsUnicodeToAnsiTable = NULL;
+PCHAR NlsUnicodeToOemTable = NULL;
+
+PWCHAR NlsUnicodeUpcaseTable = NULL;
+PWCHAR NlsUnicodeLowercaseTable = NULL;
 #endif
 
 
 /* FUNCTIONS *****************************************************************/
 
+/*
+ * Missing functions:
+ *   RtlInitCodePageTable
+ *   RtlInitNlsTables
+ *   RtlResetRtlTranslations
+ */
+
+/*
+ * RtlConsoleMultiByteToUnicodeN@24
+ */
+
+NTSTATUS
+STDCALL
+RtlCustomCPToUnicodeN (
+	PRTL_NLS_DATA	NlsData,
+	PWCHAR		UnicodeString,
+	ULONG		UnicodeSize,
+	PULONG		ResultSize,
+	PCHAR		CustomString,
+	ULONG		CustomSize)
+{
+	ULONG Size = 0;
+	ULONG i;
+
+	if (NlsData->DbcsFlag == FALSE)
+	{
+		/* single-byte code page */
+		if (CustomSize > (UnicodeSize / sizeof(WCHAR)))
+			Size = UnicodeSize / sizeof(WCHAR);
+		else
+			Size = CustomSize;
+
+		if (ResultSize != NULL)
+			*ResultSize = Size * sizeof(WCHAR);
+
+		for (i = 0; i < Size; i++)
+		{
+			*UnicodeString = NlsData->MultiByteToUnicode[*CustomString];
+			UnicodeString++;
+			CustomString++;
+		}
+	}
+	else
+	{
+		/* multi-byte code page */
+		/* FIXME */
+
+	}
+
+	return STATUS_SUCCESS;
+}
+
+
 VOID
 STDCALL
-RtlGetDefaultCodePage (PUSHORT AnsiCodePage,
-                       PUSHORT OemCodePage)
+RtlGetDefaultCodePage (
+	PUSHORT	AnsiCodePage,
+	PUSHORT	OemCodePage
+	)
 {
 	*AnsiCodePage = NlsAnsiCodePage;
 	*OemCodePage = NlsOemCodePage;
@@ -66,11 +124,13 @@ RtlGetDefaultCodePage (PUSHORT AnsiCodePage,
 
 NTSTATUS
 STDCALL
-RtlMultiByteToUnicodeN(PWCHAR UnicodeString,
-                       ULONG  UnicodeSize,
-                       PULONG ResultSize,
-                       PCHAR  MbString,
-                       ULONG  MbSize)
+RtlMultiByteToUnicodeN (
+	PWCHAR	UnicodeString,
+	ULONG	UnicodeSize,
+	PULONG	ResultSize,
+	PCHAR	MbString,
+	ULONG	MbSize
+	)
 {
 	ULONG Size = 0;
 	ULONG i;
@@ -90,7 +150,7 @@ RtlMultiByteToUnicodeN(PWCHAR UnicodeString,
 		{
 			*UnicodeString = *MbString;
 #if 0
-			*UnicodeString = AnsiToUnicodeTable[*MbString];
+			*UnicodeString = NlsAnsiToUnicodeTable[*MbString];
 #endif
 
 			UnicodeString++;
@@ -110,9 +170,11 @@ RtlMultiByteToUnicodeN(PWCHAR UnicodeString,
 
 NTSTATUS
 STDCALL
-RtlMultiByteToUnicodeSize(PULONG UnicodeSize,
-                          PCHAR MbString,
-                          ULONG MbSize)
+RtlMultiByteToUnicodeSize (
+	PULONG	UnicodeSize,
+	PCHAR	MbString,
+	ULONG	MbSize
+	)
 {
 	if (NlsMbCodePageTag == FALSE)
 	{
@@ -132,11 +194,13 @@ RtlMultiByteToUnicodeSize(PULONG UnicodeSize,
 
 NTSTATUS
 STDCALL
-RtlOemToUnicodeN(PWCHAR UnicodeString,
-                 ULONG  UnicodeSize,
-                 PULONG ResultSize,
-                 PCHAR  OemString,
-                 ULONG  OemSize)
+RtlOemToUnicodeN (
+	PWCHAR	UnicodeString,
+	ULONG	UnicodeSize,
+	PULONG	ResultSize,
+	PCHAR	OemString,
+	ULONG	OemSize
+	)
 {
 	ULONG Size = 0;
 	ULONG i;
@@ -156,7 +220,7 @@ RtlOemToUnicodeN(PWCHAR UnicodeString,
 		{
 			*UnicodeString = *OemString;
 #if 0
-			*UnicodeString = OemToUnicodeTable[*OemString];
+			*UnicodeString = NlsOemToUnicodeTable[*OemString];
 #endif
 
 			UnicodeString++;
@@ -176,11 +240,56 @@ RtlOemToUnicodeN(PWCHAR UnicodeString,
 
 NTSTATUS
 STDCALL
-RtlUnicodeToMultiByteN(PCHAR  MbString,
-                       ULONG  MbSize,
-                       PULONG ResultSize,
-                       PWCHAR UnicodeString,
-                       ULONG  UnicodeSize)
+RtlUnicodeToCustomCPN (
+	PRTL_NLS_DATA	NlsData,
+	PCHAR		CustomString,
+	ULONG		CustomSize,
+	PULONG		ResultSize,
+	PWCHAR		UnicodeString,
+	ULONG		UnicodeSize
+	)
+{
+	ULONG Size = 0;
+	ULONG i;
+
+	if (NlsData->DbcsFlag == 0)
+	{
+		/* single-byte code page */
+		if (UnicodeSize > (CustomSize * sizeof(WCHAR)))
+			Size = CustomSize;
+		else
+			Size = UnicodeSize / sizeof(WCHAR);
+
+		if (ResultSize != NULL)
+			*ResultSize = Size;
+
+		for (i = 0; i < Size; i++)
+		{
+			*CustomString = NlsData->UnicodeToMultiByte[*UnicodeString];
+			CustomString++;
+			UnicodeString++;
+		}
+	}
+	else
+	{
+		/* multi-byte code page */
+		/* FIXME */
+
+	}
+
+	return STATUS_SUCCESS;
+}
+
+
+NTSTATUS
+STDCALL
+RtlUnicodeToMultiByteN (
+	PCHAR	MbString,
+	ULONG	MbSize,
+	PULONG	ResultSize,
+	PWCHAR	UnicodeString,
+	ULONG	UnicodeSize
+	)
 {
 	ULONG Size = 0;
 	ULONG i;
@@ -220,9 +329,11 @@ RtlUnicodeToMultiByteN(PCHAR  MbString,
 
 NTSTATUS
 STDCALL
-RtlUnicodeToMultiByteSize(PULONG MbSize,
-                          PWCHAR UnicodeString,
-                          ULONG UnicodeSize)
+RtlUnicodeToMultiByteSize (
+	PULONG	MbSize,
+	PWCHAR	UnicodeString,
+	ULONG	UnicodeSize
+	)
 {
 	if (NlsMbCodePageTag == FALSE)
 	{
@@ -242,11 +353,13 @@ RtlUnicodeToMultiByteSize(PULONG MbSize,
 
 NTSTATUS
 STDCALL
-RtlUnicodeToOemN(PCHAR  OemString,
-                 ULONG  OemSize,
-                 PULONG ResultSize,
-                 PWCHAR UnicodeString,
-                 ULONG  UnicodeSize)
+RtlUnicodeToOemN (
+	PCHAR	OemString,
+	ULONG	OemSize,
+	PULONG	ResultSize,
+	PWCHAR	UnicodeString,
+	ULONG	UnicodeSize
+	)
 {
 	ULONG Size = 0;
 	ULONG i;
@@ -284,6 +397,54 @@ RtlUnicodeToOemN(PCHAR  OemString,
 }
 
 
+NTSTATUS
+STDCALL
+RtlUpcaseUnicodeToCustomCPN (
+	PRTL_NLS_DATA	NlsData,
+	PCHAR		CustomString,
+	ULONG		CustomSize,
+	PULONG		ResultSize,
+	PWCHAR		UnicodeString,
+	ULONG		UnicodeSize
+	)
+{
+	WCHAR UpcaseChar;
+	ULONG Size = 0;
+	ULONG i;
+
+	if (NlsData->DbcsFlag == 0)
+	{
+		/* single-byte code page */
+		if (UnicodeSize > (CustomSize * sizeof(WCHAR)))
+			Size = CustomSize;
+		else
+			Size = UnicodeSize / sizeof(WCHAR);
+
+		if (ResultSize != NULL)
+			*ResultSize = Size;
+
+		for (i = 0; i < Size; i++)
+		{
+			*CustomString = NlsData->UnicodeToMultiByte[*UnicodeString];
+#if 0
+			UpcaseChar = NlsUnicodeUpcaseTable[*UnicodeString];
+			*CustomString = NlsData->UnicodeToMultiByte[UpcaseChar];
+#endif
+			CustomString++;
+			UnicodeString++;
+		}
+	}
+	else
+	{
+		/* multi-byte code page */
+		/* FIXME */
+
+	}
+
+	return STATUS_SUCCESS;
+}
+
+
 NTSTATUS
 STDCALL
 RtlUpcaseUnicodeToMultiByteN (
@@ -294,6 +455,7 @@ RtlUpcaseUnicodeToMultiByteN (
 	ULONG	UnicodeSize
 	)
 {
+	WCHAR UpcaseChar;
 	ULONG Size = 0;
 	ULONG i;
 
@@ -310,10 +472,10 @@ RtlUpcaseUnicodeToMultiByteN (
 
 		for (i = 0; i < Size; i++)
 		{
-			/* FIXME: Upcase!! */
 			*MbString = *UnicodeString;
 #if 0
-			*MbString = UnicodeToAnsiTable[*UnicodeString];
+			UpcaseChar = NlsUnicodeUpcaseTable[*UnicodeString];
+			*MbString = NlsUnicodeToAnsiTable[UpcaseChar];
 #endif
 
 			MbString++;
@@ -341,6 +503,7 @@ RtlUpcaseUnicodeToOemN (
 	ULONG	UnicodeSize
 	)
 {
+	WCHAR UpcaseChar;
 	ULONG Size = 0;
 	ULONG i;
 
@@ -357,10 +520,10 @@ RtlUpcaseUnicodeToOemN (
 
 		for (i = 0; i < Size; i++)
 		{
-			/* FIXME: Upcase !! */
 			*OemString = *UnicodeString;
 #if 0
-			*OemString = UnicodeToOemTable[*UnicodeString];
+			UpcaseChar = NlsUnicodeUpcaseTable[*UnicodeString];
+			*OemString = UnicodeToOemTable[UpcaseChar];
 #endif
 
 			OemString++;
diff --git a/reactos/ntoskrnl/ntoskrnl.def b/reactos/ntoskrnl/ntoskrnl.def
index ad0fd1d8c60..01551fb405d 100644
--- a/reactos/ntoskrnl/ntoskrnl.def
+++ b/reactos/ntoskrnl/ntoskrnl.def
@@ -1,4 +1,4 @@
-; $Id: ntoskrnl.def,v 1.71 2000/05/09 21:31:01 ekohl Exp $
+; $Id: ntoskrnl.def,v 1.72 2000/05/13 01:46:22 ekohl Exp $
 ;
 ; reactos/ntoskrnl/ntoskrnl.def
 ;
@@ -481,7 +481,7 @@ RtlCreateAcl@12
 ;RtlCreateRegistryKey
 RtlCreateSecurityDescriptor@8
 RtlCreateUnicodeString@8
-;RtlCustomCPToUnicodeN
+RtlCustomCPToUnicodeN@24
 ;RtlDecompressBuffer
 ;RtlDecompressChunks
 ;RtlDecompressFragment
@@ -604,7 +604,7 @@ RtlUnicodeStringToCountedOemString@12
 RtlUnicodeStringToInteger@12
 RtlUnicodeStringToOemSize@4
 RtlUnicodeStringToOemString@12
-;RtlUnicodeToCustomCPN
+RtlUnicodeToCustomCPN@24
 RtlUnicodeToMultiByteN@20
 RtlUnicodeToMultiByteSize@12
 RtlUnicodeToOemN@20
@@ -614,7 +614,7 @@ RtlUpcaseUnicodeString@12
 RtlUpcaseUnicodeStringToAnsiString@12
 RtlUpcaseUnicodeStringToCountedOemString@12
 RtlUpcaseUnicodeStringToOemString@12
-;RtlUpcaseUnicodeToCustomCPN
+RtlUpcaseUnicodeToCustomCPN@24
 RtlUpcaseUnicodeToMultiByteN@20
 RtlUpcaseUnicodeToOemN@20
 RtlUpperChar@4
diff --git a/reactos/ntoskrnl/ntoskrnl.edf b/reactos/ntoskrnl/ntoskrnl.edf
index 0cb587ae2dd..db84c9de0af 100644
--- a/reactos/ntoskrnl/ntoskrnl.edf
+++ b/reactos/ntoskrnl/ntoskrnl.edf
@@ -1,4 +1,4 @@
-; $Id: ntoskrnl.edf,v 1.58 2000/05/09 21:31:01 ekohl Exp $
+; $Id: ntoskrnl.edf,v 1.59 2000/05/13 01:46:23 ekohl Exp $
 ;
 ; reactos/ntoskrnl/ntoskrnl.def
 ;
@@ -469,6 +469,7 @@ RtlCopyUnicodeString=RtlCopyUnicodeString@8
 RtlCreateAcl=RtlCreateAcl@12
 RtlCreateSecurityDescriptor=RtlCreateSecurityDescriptor@8
 RtlCreateUnicodeString=RtlCreateUnicodeString@8
+RtlCustomCPToUnicodeN=RtlCustomCPToUnicodeN@24
 RtlDowncaseUnicodeString=RtlDowncaseUnicodeString@12
 RtlEnlargedIntegerMultiply=RtlEnlargedIntegerMultiply@8
 RtlEnlargedUnsignedDivide=RtlEnlargedUnsignedDivide@16
@@ -546,6 +547,7 @@ RtlUnicodeStringToCountedOemString=RtlUnicodeStringToCountedOemString@12
 RtlUnicodeStringToInteger=RtlUnicodeStringToInteger@12
 RtlUnicodeStringToOemSize=RtlUnicodeStringToOemSize@4
 RtlUnicodeStringToOemString=RtlUnicodeStringToOemString@12
+RtlUnicodeToCustomCPN=RtlUnicodeToCustomCPN@24
 RtlUnicodeToMultiByteN=RtlUnicodeToMultiByteN@20
 RtlUnicodeToMultiByteSize=RtlUnicodeToMultiByteSize@12
 RtlUpcaseUnicodeChar=RtlUpcaseUnicodeChar@4
@@ -553,6 +555,7 @@ RtlUpcaseUnicodeString=RtlUpcaseUnicodeString@12
 RtlUpcaseUnicodeStringToAnsiString=RtlUpcaseUnicodeStringToAnsiString@12
 RtlUpcaseUnicodeStringToCountedOemString=RtlUpcaseUnicodeStringToCountedOemString@12
 RtlUpcaseUnicodeStringToOemString=RtlUpcaseUnicodeStringToOemString@12
+RtlUpcaseUnicodeToCustomCPN=RtlUpcaseUnicodeToCustomCPN@24
 RtlUpcaseUnicodeToMultiByteN=RtlUpcaseUnicodeToMultiByteN@20
 RtlUpcaseUnicodeToOemN=RtlUpcaseUnicodeToOemN@20
 RtlUpperChar=RtlUpperChar@4
diff --git a/reactos/ntoskrnl/rtl/nls.c b/reactos/ntoskrnl/rtl/nls.c
index 778ca261ec0..ac427ddec1c 100644
--- a/reactos/ntoskrnl/rtl/nls.c
+++ b/reactos/ntoskrnl/rtl/nls.c
@@ -1,4 +1,4 @@
-/* $Id: nls.c,v 1.3 2000/03/03 00:48:50 ekohl Exp $
+/* $Id: nls.c,v 1.4 2000/05/13 01:45:40 ekohl Exp $
  *
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS kernel
@@ -54,9 +54,46 @@ CHAR UnicodeToOemTable [65536];
 
 /* FUNCTIONS *****************************************************************/
 
-/*
- * RtlCustomCPToUnicodeN
- */
+NTSTATUS
+STDCALL
+RtlCustomCPToUnicodeN (
+	PRTL_NLS_DATA	NlsData,
+	PWCHAR		UnicodeString,
+	ULONG		UnicodeSize,
+	PULONG		ResultSize,
+	PCHAR		CustomString,
+	ULONG		CustomSize)
+{
+	ULONG Size = 0;
+	ULONG i;
+
+	if (NlsData->DbcsFlag == FALSE)
+	{
+		/* single-byte code page */
+		if (CustomSize > (UnicodeSize / sizeof(WCHAR)))
+			Size = UnicodeSize / sizeof(WCHAR);
+		else
+			Size = CustomSize;
+
+		if (ResultSize != NULL)
+			*ResultSize = Size * sizeof(WCHAR);
+
+		for (i = 0; i < Size; i++)
+		{
+			*UnicodeString = NlsData->MultiByteToUnicode[(int)*CustomString];
+			UnicodeString++;
+			CustomString++;
+		}
+	}
+	else
+	{
+		/* multi-byte code page */
+		/* FIXME */
+
+	}
+
+	return STATUS_SUCCESS;
+}
 
 
 VOID
@@ -186,9 +223,47 @@ RtlOemToUnicodeN (
 }
 
 
-/*
- * RtlUnicodeToCustomCPN
- */
+NTSTATUS
+STDCALL
+RtlUnicodeToCustomCPN (
+	PRTL_NLS_DATA	NlsData,
+	PCHAR		CustomString,
+	ULONG		CustomSize,
+	PULONG		ResultSize,
+	PWCHAR		UnicodeString,
+	ULONG		UnicodeSize
+	)
+{
+	ULONG Size = 0;
+	ULONG i;
+
+	if (NlsData->DbcsFlag == 0)
+	{
+		/* single-byte code page */
+		if (UnicodeSize > (CustomSize * sizeof(WCHAR)))
+			Size = CustomSize;
+		else
+			Size = UnicodeSize / sizeof(WCHAR);
+
+		if (ResultSize != NULL)
+			*ResultSize = Size;
+
+		for (i = 0; i < Size; i++)
+		{
+			*CustomString = NlsData->UnicodeToMultiByte[*UnicodeString];
+			CustomString++;
+			UnicodeString++;
+		}
+	}
+	else
+	{
+		/* multi-byte code page */
+		/* FIXME */
+
+	}
+
+	return STATUS_SUCCESS;
+}
 
 
 NTSTATUS
@@ -304,9 +379,48 @@ RtlUnicodeToOemN (
 }
 
 
-/*
- * RtlUpcaseUnicodeToCustomCPN
- */
+NTSTATUS
+STDCALL
+RtlUpcaseUnicodeToCustomCPN (
+	PRTL_NLS_DATA	NlsData,
+	PCHAR		CustomString,
+	ULONG		CustomSize,
+	PULONG		ResultSize,
+	PWCHAR		UnicodeString,
+	ULONG		UnicodeSize
+	)
+{
+	ULONG Size = 0;
+	ULONG i;
+
+	if (NlsData->DbcsFlag == 0)
+	{
+		/* single-byte code page */
+		if (UnicodeSize > (CustomSize * sizeof(WCHAR)))
+			Size = CustomSize;
+		else
+			Size = UnicodeSize / sizeof(WCHAR);
+
+		if (ResultSize != NULL)
+			*ResultSize = Size;
+
+		for (i = 0; i < Size; i++)
+		{
+			/* FIXME: Upcase!! */
+			*CustomString = NlsData->UnicodeToMultiByte[*UnicodeString];
+			CustomString++;
+			UnicodeString++;
+		}
+	}
+	else
+	{
+		/* multi-byte code page */
+		/* FIXME */
+
+	}
+
+	return STATUS_SUCCESS;
+}
 
 
 NTSTATUS