How do I add an audio track to my "Play To" list using C# in Windows 7?

I poked around for a while on Google and Windows Media player looking for a way to do this, but I can't and I think I should be able to, so I'm asking the fine people of StackOverflow.

I'd like to be able to write some code to do one of the following:

1. Add an audio file from my WMP media library to the current "Play To" playlist.
2. Add an audio file from the file system to the current "Pla开发者_开发百科y To" playlist.

It doesn't really matter to me which of these I use for my approach. Can anyone give me some direction? I'm guessing I'm going to have to dig into the Windows Media Player DLLs, but a starting point would be really helpful.

As far as I know, there is no easy way to do this. I guess you could try wrapping this in C#, but it isn't that documented.