Yes you can, I have done this many times via either of two options:
1. Add your AB number to your booking which will show the appropriate oneworld status allowing extra luggage and lounge access. Then prior to boarding (either on exiting the lounge or at the gate) ask for the number attached to the booking to be changed to your US number.
2. Add your US number to your booking, and at checkin/lounge produce your AB card showing the appropriate oneworld status. Ensure the agent does not change the number attached to the booking.
Thank you so much for your help!