Sending proper Combi # changes from ext midi controller

[ILM4axe]

Hi forum members,

I'm new to Midi controllers and I'm trying to understand how to issue a combi # change command from an external midi controller. Basically, I'm using a midi foot controller to simultaneously select my guitar, keyboard, and Roland drum sampler patches. I'm trying to, that is!

I understand that I must assign each device its own midi channel, and I understand that the guitar and drum patches basically use patches 0-999. But how do I tell the Korg X50 to change to....Combi Bank C Patch 109, for example?

Any advice would be appreciated....I'm obviously WAY behind the curve here.

Thanks,
Jim