LdrGetProcedureAddress

NTSYSAPI 
NTSTATUS
NTAPI


LdrGetProcedureAddress(



  IN HMODULE              ModuleHandle,
  IN PANSI_STRING         FunctionName OPTIONAL,
  IN WORD                 Oridinal OPTIONAL,
  OUT PVOID               *FunctionAddress );

FunctionName

Is optional, but you must declare one of FunctionName or Oridinal. In Microsoft concept, you should use both parameters, for faster function implementation. But there's a bug in link.exe, and all oridinals in PE executables are wrong...

Requirements:

Library: ntdll.lib

Undocumented functions of NTDLL

FunctionName