Did you try installing an old version of AHI and then setting the HippoPlayer to use AHI drivers only for audio output? It might be able to stream it from the hard drive then. (Or I could be wrong about Hippoplayer being able to do stuff like that.)
As for the formats HippoPlayer supports, it supports many music module formats including Protracker, MedPlayer (with the appropriate playback library), AHX, and many, many others.