If you take it to RB you can split the piano into left and right hand if that would help.

Also, if you're bound and determined to do it you might try (again in RB) copying the piano track and paste it to an empty track, select it, then use split drums (edit - split midi drums) to separate tracks. Then right click each new track and change midi track to whatever you want. I haven't tried it but I think it should work.

Jim