i had the mc303 for years, and at somepoint i controlled it from Cakewalk, EVERY parameter in realtime. I think this is what you want to do.

search the net for groovebox sites explaining how to control it as a SOUND MODULE (this is the secret)

If you use Cubase, you'll need a MIXERMAP to tweak the knobs and record movements in realtime, under Cakewalk the equivalent is called a GROOVEWARE PANEL I think.

once everything is plugged together (and the gbox in MODULE mode), it's as easy as controlling ANY midi module/racks, since it's multitimbral (16 parts/channels/instruments running at the same time)

good luck.