An imaginative set of routes from Air Wales which might work.
BA have tried CWL-NCL and Air Wales have tried CWL-MAN in the not too distant past, neither of which was successful.
I though bmibaby might have tried CWL-NCL given the apparent success of easyJet's BRS-NCL (third daily rotation being added from December).
This triangular set of routes might cut the mustard. The only weakness is that the timings do not make a daytrip from CWL to LPL possible unless you travel via NCL, if that is allowed, and in any case that way is a bit of a jaunt for a day trip.
Good luck to them. I shall watch with interest.