Crop or matte should work.
Does the talent interact with that spot, or is it always just background? If the latter, simply use a Crop or Garbage Matte to hide it.
Safe Harbor Computers
I tried cropping and garbage matte but since it is panning it doesn't work as well. What I need is a mask really like in After Effects as sometimes the actors hide the spot and sometimes they don't. It's only a small white square but it's visible on the background image.
I would do this in Ae with the tools specifically designed for this purpose.