I am coming up on 12 years sober with AA as the vehicle that got and keeps me sober. I have a spiritual basis, but not a belief in God per se. If you care to get the details feel free to private message me. I know several members of the fellowship that are either agnostic or have what would be called an unconventional view of a higher power.
As was suggested earlier by BadCompany, don't enter AA with an agenda, just a need to stop drinking and you will be amazed what is possible.
In my first meeting I asked the guy next to me "is there a non-religious meeting somewhere?" He smiled and suggested that I "just keep coming back." He and I shared a speaker’s dais last Sunday where we both recounted to the auditorium how it is the fellowship and support of AA that makes sobriety possible if you are sincere and willing to do the work. We find after some time that few of us are the same people who walked into that first meeting.
I hope you find what you are looking for, don't bring preconceived notions with you, just the desire to stop drinking and I am quite sure that you will be glad you came.
Jon