You should be able to do it with GPSGate. Haven't tried it, but I remember reading on their forums that someone was using an ipaq with gpsgate to make the ipaq appear as a bluetooth GPS.
I know for a fact the desktop version can do it, so give it a try and see how it works.
EDIT: Here are those ipaq instructions which should work perfectly fine on the Mogul
http://franson.com/forum/topic.asp?TOPIC_ID=3968