Sorry, I have made mistake...Nvarchar belongs to MS SQL data type but, regardless, if you format it as "text", it should work on the same way as I said in previous message. Further on, did you try to directly type special Croatian letters e.g., Č,Ć.Š,Đ and Ž into table(s) in order to see the outcome. If you get correct recording it means that your issue is not related to the Access? Check it...Or, try to enter special characters via Access form and to see outcome...
your issue is the most probably related to the UTF-8 character set not setup (of course, if you face the same problem with all special Croatian chars i.e., ČĆŠĐŽ). Namely, in the interface layer that lies between user and the DB itself, e.g., Ruby or PHP or Iron Speed application or etc...there is place to setup UTF -8 as the default character set. It could be e.g., PHP.ini file or Apache etc...Google little bit around these things....Personally, for your info, I am currently with the Iron Speed on the platform of Client-Server tipe (DB is MS SQL Server but could be Access equally, MySQL ...), DB is on the server powered by Windows 2003, everything related to the special Croatian or Serbian Cyrillic characters works perfectly well. (Special Cyrillic letters are: Č=Ч,Ć=Ћ,Š=Ш,Đ=Ђ,Ž=Ж respectively and for your info if needed)