Tracking BitBlts system wide

I saw the mirror video driver in DDK samples. I am new to device driver development and need help with the following -

  1. Track calls to Win32 BitBlt API in the driver. Where/how exactly to modify the sample driver to do this?
  2. Identify the window corresponding to the device contexts in the original BitBlt call. I was not sure how to get the original Win32 DC handle from the SURFACE parameters that are part of the EngBitBlt/DrvBitBlt call.