Roland EXR-5 questions

I'm new to the forum and not primarily a key player, but rather guitar. So, I need some help. I have a Roland EXR-5. Can anyone tell me if the default MIDI channel 4 that it transmits data on can be changed to one of the other channels? I use an Alesis MMT-8 sequencer, but when I MIDI the keys to the sequencer and record a MIDI track, it always does it on MIDI 4. How in the world to I change channels to add other parts? Or is this not possible. Second question: In split mode I like running a bass guitar on the left hand. Problem is, in the middle of a song, while playing in real time, I may want to change my right hand from, say, a piano, to an organ. In my case, the left hand voice also changes when I do this to something OTHER than bass. Is there a way to keep the bass voice on the left hand while changing right hand voices on the fly? THANKS LG

I have a Roland EXR-7, which I think should work the same as your EXR-5. For the first question, you probably should check the manual. I haven't really bothered much with the MIDI stuff yet, so I'm unable to answer the question.
About the split problem: Go to FUNCTION, then KB SET. Somewhere among those parameters is an SplitDual, or something like that that is set to "Auto" by default. Change it to "manual" and the problem will be solved.
Hope this helps you out.