How do I get an upgrade on a US Airways flight when on a US flight booked under a United ticket. My corporate travel agent booked me a flight (CLT-SFO) for next week. It is a US operated flight. I'm a Silver Preferred Dividend Miles member. I have seen on this board that I can get an upgrade to FC, but not through the automatic upgrade system. Does anyone know the best way to pursue a FC upgrade when flying on a US operated flight under a United ticket. If not FC, can I get a preferred seat near the front rather than be stuck in the back.

Thanks !