I can't answer the Microsoft Media Foundation, specifically. Sorry. And it sounds like you'll have the background to do the research at least as well as I could (and you certainly will have more motivation to do so, *grin*).

But you can definitely set up references in a VBA project to access (no pun intended) outside addins (whether COM or DLLs/OCX you've developed in Visual Studio or some other platform).

It may help you to go into the VBA developer interface in one of the office appliations, and check out Tools > References. Also, in 2007 and later, there is generally a Developer tab on the main application window, which allows you to view (and add) addins and COM add-ins. How you programmatically use those addins would, of course, depend on how they are built, but it's not hard.