Ok thanks for that. So on the assumption that they are occupied queen cells, this is what I'm thinking of doing - do feel free to let me know if you think I'm not doing the right thing as I've never done this before...
I have a brand new polystyrene nucleus box I bought the other day. I'll remove one frame with the queen and quite a few bees on it, fill the built in feeder and plug the entrance until evening, moving it a little way away from the main hive.
I'll remove one of the queen cells and leave the other, checking in about three weeks to see if the queen has mated and is laying.
The main thing I'm not sure about is re-uniting the nuc bees. Won't they have re-orientated to the new position and keep flying back there if I re-introduce them to the old hive? I don't really want another colony so I'm not sure what to do with the eggs, frames and bees from the nuc.