mrso144 wrote:
to make it simple, can i take my macbook to apple and ask them to fit language specific keys (e.g. Croatian letters) to a keyboard which was not designed for that language (e.g. US keyboard)?
To find out whether you can swap your current keyboard for the Croatian version (as shown at https://support.apple.com/en-us/HT201794 ) and how much that would cost, you will need to contact Apple stores or service operations in your country directly yourself. Nobody in these forums represents Apple sales or repair.
I don't know whether Croatian keyboard machines are available anywhere outside that country (they are not sold in the US). You would have to check each country's online Apple store to determine whether such machines are available there. Apple stores do not ship outside their own country.
Apple does make machines with a Croatian keyboard