Hi ck1 You could chase it into the plaster up to the ceiling corner cut a groove into the wall or ceiling round the room then back down new chase to new socket very dusty and not for the feint hearted then you need to plaster fill the chases best time is next time you decorate HTH Tez
Do what most of us in`t north do have it dangling from one side ert room tert t`uther, hey presto it doubles up as in in-door washing line :)
(sorry couldn`t resist and BTW i`m a northener)
Try taking the cable up the wall and covering with conduit going up into the loft space and coming out where you need the new position for the aerial. That is if you have a bungalow!!