Controlling existing Powerpoint files with C#

Well, I'm doing some research for my college; we're trying to figure out the best way of designing our own digital signage system, and we'd like to stick with Powerpoint if we can, simply because it's really easy for the members of the Student Administrative Council to make their content that way.

So, essentially, I'd like to know how I could load Powerpoint slideshows into a window, run them, and otherwise manipulate and control them using C#. (The reason being I need to keep part of the screen open for other things like an RSS feed, and other widgets that they might want to load in.)

All help is appreciated, and thank you for taking the time to read my post.