Anthony,
I have done something similair. I want to do a "minority Report" type of thing, where Tom Criuse moves holographic computer screens around in midair, using AE. I needed screen shoots from a PC.
I just used a laptop, with a S jack. I plugged the camcorder into the S jack, and was able to record anything on the computer screen.
Find/borrow a laptop with a S jack. Plug your camcorder in, play the Powerpoint slides, and record. Next you can capture the footage from your camcorder.