Without seeing your source footage and your layer stack nobody can tell you much. Apparently this uses some sort of screening or roto, but we simply don't know how you arrived at what we are looking at and cannot understand your process.
Mylenium is right.
The short answer is going to be keying or rotoscoping to get the hands over the solid you've created, but without knowing more, we can't tell you more.
It looks to me like those artifacts may be the result of color correction. If switching your project 232 bit doesn't fix it and the camera is moving then you will need to stabilize or track the motion in the shot, create a mask, then craft a replacement for that window. You will want to replace the entire window. I would do that in Photoshop. Then you need another copy of the footage and you need to Roto just the hands and put it on top of the replacement window. This is real basic compositing technique.
Please let us know if any of that makes sense. It does not tell us what part you don't understand and we will try to point you to some learning resources. For example if you do not have any idea how to rotoscope then type rotoscope in the search help field at the top right corner of the app and study up on the community resources for that subject.
thank you for the replies.
I understood the problem.Thanks a lot for these suggestions.