Windows 7 Media Center - How to add Video Meta Data?

I'm creating video files in several formats (DivX, Wmv, M4v, etc) for use exclusively on Windows 7 Media Center (not Media Player) th开发者_如何学编程at are not from DVD.

Is it possible to attach descriptions, tags etc to these files such that they appear in Media Center the way that they for WTV and DV-RMS files?

I've tried editing the File | Details using the properties dialog but no effect. Is there something like a dvdid.xml equivalent?

I'm hoping if it's possible for something XML or that I can do with .NET but straight Win32 is possible as well.