Made a small plugin that allows you to use both Windows Media Player dynamic playlists and regular static (non M3U) playlists from within PMS. Shows up as an Additional Folder at Root ("Dynamic Playlists").
The Dynamic Playlist function queries the PMS media database, not WMP's, so it's not as robust. ie, not as many fields can be queried against as they're not in the DB.
Works well enough for me, so if there's any interest, I'll clean it up and comment the code and find a place to put it.