I can't see why not. You can check luggage through on BA even if you have two separate PNRs (e.g. CDG-LHR then LHR-JFK), so logically, if you do MCT-AUH then AUH-LHR your luggage should be checked through to final destination.

The only question is whether the luggage routing systems are intelligent enough to realise that the bag shouldn't be offloaded at AUH as it'd have to be loaded straight back on again.

But this is just conjecture as I've never done it...