model c split organ

I have two keyboards and I want to configure them like the two manuals on a model C. I load the Init Model C Split preset in halion sonic 2 but am having trouble. I cannot figure out how to change the split point. I have one keyboard transmitting on midi channel 1 and the other on channel 2. Is there any documentation for the init model c preset. I have read the manual and am no farther ahead. What do other people do to emulate a two keyboard organ setup?