What I have always wanted to do was to be able to "Cut and Paste" Video.

Where I take Video A = An old woman talking
Video B = A kid sitting in a chair

Where I can cut the head off the woman in video A
and put it over the video of the child in video B

and be able to play both of the videos at once overlapping
While only saving the cut images

So that the old womans head would be on the childs body

I don't need it to be too detailed just for entertainment.

I own Vegas 6, and would like to do this, but do not know what program offers it, I do not believe it is possible with Vegas but is it?