Axe-Fx - GCP Yamaha FC7 exp pedal basic questions

[hamrhed1]

My GCP is setup with 4 buttons for presets and 8 for instant access control.

The instant access buttons seem to work fine and I have downloaded some presets that have bypassed effects and the buttons do turn on the effects when I press them, so that part is working fine.

One of the patches has a bypassed WAH in it. My instant access button does in fact turn onthe WAH, I can hear it BUT...my Yamaha FC7 expression pedal doesn't seem to do anything when I press it. It doesn't seem to work when I plug it into the back of the Axe or the GCP exp
pedal jacks.

There are expression pedal jacks (1 and 2) on the back of the Axe-fx and I also have exp pedal jacks on the GCP. So one basic question is "Can you use them interchangeably once they are set up for an effect?" (in other words, once you have configured an effect to use EXP 1; can you
plug it into either the back of the Axe-fx in exp-1 jack OR the exp 1 jack on the GCP OR does it have to be a specific exp pedal jack)

And, what exactly am I missing in getting this pedal to work now that I have enabled the WAH?

Can somebody please provide the exact steps to make this pedal work?