Dubai/BA "R" class?

So I am in Dubai, and it is amazing... I recommend the Jumeirah Beach Hotel to everybody!
Went to the Burj Al Arab for afternoon tea and what a treat it is, the cost isn't too bad either (~£40pp). I will do a TR as soon as I return, I promise [:w] Thanks to everybody for their info, it has come in very useful.
Anyway, could anyone tell me if R class on BA domestic is changable to an earlier flight (LHR-EDI) and will it get me into the terraces lounge, as we have a longgg wait at LHR on the return leg. VS400 was excellent, PE service was amazing and we are looking forward to the return leg (does anybody think it would be possible to Upgrade on the return leg at the airport and how much would it be from pe (H class) for 3 of us?)

John

Anyway, could anyone tell me if R class on BA domestic is changable to an earlier flight (LHR-EDI) and will it get me into the terraces lounge, as we have a longgg wait at LHR on the return leg. VS400 was excellent, PE service was amazing and we are looking forward to the return leg (does anybody think it would be possible to Upgrade on the return leg at the airport and how much would it be from pe (H class) for 3 of us?)

John