You can choose the FFP you want the miles to go to. Just call anytime, or you can do it at the kiosk's at the airport (maybe even online checkin). You can certainly have the each direction to credit to different programs. You can just leave your AP number on the reservation, and change it to ANA when checking in for your return flight (or call and change it with a reservations agent for your retrurn after your outbound). Or, you can book using your ANA number, and then change it back to AP before your return flight.