I returned a GCP within 1 day of receiving it, when I bought my Axe FX II in May 2012. I could tell it was not up to the task. The AXE has too many features that won't be accessible without a better controller - MFC, Liquid Foot, RJM, Goliath.
You MIGHT be able to assign the 1/4" input on the back of the AXE to advance through scenes in sequential order. If you want MIDI control for that with the GCP, you are going to have to buy a few items from MIDI SOLUTIONS to get it accomplished. By the time you've spent the GCP money PLUS a couple of MIDI SOLUTIONS boxes, you could have purchased a Liquid Foot JR and had 1,000 times more capability....maybe 5,000 times the capability.