I'm not on my working PC right now, so I can't guide you, but If you look at the space navigator settings you should be able to figure out that there is a way as well to generate as to import XML-Shemes. That's the way to use my file.
I've tried to use your .xml file but I can't work out what to do with it. I'm using a SpacePilot Pro but I wouldn't expect the software to operate differently, I'd really like to get decent navigation in UDK.
Any help would be appreciated.