All you need to do is have a rating current then send off the paperwork to the CAA - so you'd have to do an SE(P) or ME(P) - probably be just as cheap in Europe because all you'll need is one flight or two and the flight with the examiner. It's not a whole CPL again it's just the rating portion required as to "renew your license" is just a paperwork exercise.
Flying for Fun made a good post at :
http://www.pprune.org/professional-p...ml#post6404955