Read the very helpful Help file in Vegas7 on Bezier masking. This will clearly show you how to mask an item from the rest of the video. For you, this would mean masking the Person from the the same Event background.

Another way, and this is why I was asking to see the Person and that background, would be to Chroma Key "out" close by sections of the background and then ALSO use Bezier masking to remove the rest.

Once you can do some of each of these then you place the Person on track1 and the NEW background on track 2.

You have some work to do. Read up on Bezier Masking and Chroma Keying in the help file.

Regards

Grazie