Here's the GML I've been using. I updated the one in the MC Extras folder with all of the commands that have been added since it was created. Not all of the commands will work with all versions of MC, and some of them, if you want to use them, may have to be tweaked with your specific parameters, but I've tested all of the commands I could. (I don't have a handheld so I couldn't test those, for instance). It includes a version that uses MC11.exe and a version that uses mjextman.exe. I'm not sure at which version MC stopped using mjextman and started using MC11, though.
Also, the zone-specific playback controls haven't been updated. I'll do that later if I can figure out a really quick way to do it.
Click here to download it.(You'll probably have to right-click and choose Save Target As, since it's an XML file and IE will just display it)