I tried accessing the player remotely before, but failed to do so. For that reason I created a plugin, as it allows me to send basically anything to WMPlus. Right now I think I'll keep it that way. I can respond to basically anything in the plugin, from song position changes to swapping CDs (although you can also do that without WMP, but that's besides the point) or accessing the complete media library, as well as basically everything else in the player...
But if you want to send me details on how to access WMP remotely, I'm always interested... never know when it might come in handy