I'm interested in making a presentation video of some of my PowerPoint lectures such that students can review online.  A key feature I use during lectures is real-time annotation, meaning informal sketches, doodles, etc.  I'm using PowerPoint 2010.

Is it possible to include these sketches along with narration on the presentation video?  I don't mean the final, saved annotations (which is easy to do), but the actual real-time rendering of the sketch?  I can't find any reference to this on the internet.