The expression pedal inputs work on a per-bank basis, where every bank has a different expression preset. Each expression preset has 16 midi messages that you can program. By changing banks on the MC6, you can send different CC messages. You can also send different CC messages in each expression preset in the same bank by using your standard presets A-L. By programming a Select Exp Message midi type in your preset, you can select which of the 16 midi messages in your expression preset to be active. Hence, when using your expression pedal, only the selected messages will be sent out.