is it a newer model? I believe that the keyboard is a part of the upper case component on the 2013 & 2014 retina MacBook Pro, so if Apple did it, they'd probably only be willing to replace the whole upper case (some parts are glued in place) and not dismantle it in an attempt to replace only the keyboard
That said, since they sell foreign keyboards as an original equipment option for macbook pros (at least they do in the USA), they should be able to order the upper case assembly with a different language keyboard and install it........but expect it to be very pricey
Are the keys removable on your model? If they are you could just move them and replace language specific keys. I've moved keys on a 2007 MB and current wireless keyboard (Dvorak layout). Individual keys are expensive, but I believe available.