Novak m2 dig with gt3c

[Rc crawler 219]

I have really tried searching to find the answer on here but I'm going to have to breakdown and ask. I am in the process of building a berg with the m2 esc (not my best choice but I'm going to have to ride this mistake out). I recently hacked my gt3c so I could use the ch3 trim to control the dig, the dual rate to do proportional and the ch3 button to zero out everything. I am trying to get everything to work right but with no luck. I think my problem is when I am programming the esc and I get to the part where I choose the channel I want to use for the dig I am not doing it correctly. Can someone please point me in the right direction? Thanks in advance for any and all help.
Josh