Good luck.
I checked out the SD2 manual. It is really very primitive in its midi implementation!!

Sorta like comparing DOS to Windows.

You would think they would have a midi editing section (as does just about every other midi device) to allow simple switching of MIDI transmission channels.

It would seem with the SD2, having a sequencer is a MUST HAVE if you want to do anything except just play SMF files.

Not many editing facilties are there?

And to make it even tougher there does not seem to be any sort of PC editor program available either!!!

Still if the OP can advise what his other gear is, it might be easier to assist.
Dennis