Start / stop i-arpeggiator with midi controller / foot pedal?

[swoody]

I use my Jupiter-XM for live performance with a full-size midi controller keyboard (Arturia Keylab) and am slowly getting to grips with it. Having got some control of part volumes now, I'd like to be able to start / stop the i-arp using a foot pedal ideally, or a pad on the controller, instead of the rather small 'on/off' button on the XM. Having looked through the manual, I can see how to assign this to the SL1/2/3 buttons. but not an external controller.
Any suggestions? Can I do this via midi CC?