What is aLPCVOID, LPTSTR and a va_list *Arguments?

[ToddAndMargo via perl6-users]

Hi All,

In the following C code

DWORD FormatMessageW(
         DWORD   dwFlags,
         LPCVOID lpSource,
         DWORD   dwMessageId,
         DWORD   dwLanguageId,
         LPTSTR  lpBuffer,
         DWORD   nSize,
         va_list *Arguments

What do I tell Native Call the follow are?
    LPCVOID
    LPTSTR
    va_list *Arguments


Many thanks,
-T