[DllImport("Rpcrt4.dll",EntryPoint="UuidFromStringA",SetLastError=true, CharSet=CharSet::Ansi, ExactSpelling=true, CallingConvention=CallingConvention::StdCall)]

extern "C" long UuidFromStringA( unsigned char * StringUuid, UUID * Uuid);

UuidFromStringA(UuidSringPtr, UuidPtr);