"I must quickly assure you that A.A.'s tread innumerable paths in their quest for faith. ... You can, if you wish, make A.A. itself your 'higher power.' Here's a very large group who have solved their alcohol problem. In this respect they are certainly a power greater than you, who have not even come close to a solution. Surely you can have faith in them. Even this minimum of faith will be enough." Twelve Steps and Twelve Traditions, William G. Wilson, page 27.
As a Buddhist in AA I too struggled with the God thingy. What I come up with is my own understanding of what a higher power is for me: I believe the totality of AA is God in a non-deist way. This way I can respect my cherish beliefs and work a personal program that borrows from the AA program. It works exceedingly well for me.