No problem...it just gets added on to your licence just like any other rating. After you have paid your money to the CAA of course!! No gotchas. I did mine in the USA and had no problems adapting to the UK airspace. Lets face it...as a commercial pilot you should be able to fly anywhere in the world once you have familiarised yourself with the relevant countries laws and idiosynchronies. You should complete it in Spain a lot quicker than here anyway because of the better Wx. As regards standards,they do vary but I think they do even here withinthe UK
Good luck whichever route you take
