read a video playing on screen with uploading it as a file in matlab

I need to read a video being played in a windows 7 laptop using matlab using screen capture.I can find the coordinates of rectangular window using position point tool.

This a video of moving colored spots of irregularly shape i.e. not circle, square etc. My aim is output a signal (binary 1) whenever a red color spot is observed in video(i know predefined thresholds of this red color using colorThreshold app in matlab 2014) . I do not need to visualize red color, i need a signal. The main point here is I do not wanna do it by uploading the video in matlab but instead by reading certain rectangular region of laptop's screen .The video's frame rate is 60 hz. I think basically i am trying to read red color in a rectangular region which refreshes every 1/60 second.

Thanks