vxd的通信问题

请问下列程序是何问题？能否给出调用vxd缓冲区数据的具体方法？
void main()
{
   ...
   unsigned short* BufferAddr;
   hDevice=CreateFile(\"\\\\\\\\.\\\\CLOCK.VXD\",0,0,0,CREATE_NEW,FILE_FLAG_DELETE_ON_CLOSE,0);
...
if ( !DeviceIoControl(hDevice,W32IF_PASS_FINE,hEventToNotifyApp,sizeof(hEventToNotifyApp),&BufferAddr,sizeof(BufferAddr),0,NULL))
....
  printf(\" %d \", BufferAddr);
....
  CloseHandle(hDevice);

}

你到底想问什么问题？