Mac,
The answer is an easy one, you need Adobe Presenter, a plug
in to PowerPoint. It can be purchased through the Adobe agent you
purchased your Connect account from or I can work with you for
that. Just PM me if you want.
Another option that may work is to use Captivate 3, and
import the PPT slides and record audio that way, but if you don't
have Captivate, then presenter will probably be the better option.
Jorma@RealEyes