fopen file with "special" characters in filename

Question

With this code I'm able to process any file, except for those that contain "special" characters such as accented letters (à, è, ì, ò, ù ...) and the letters of oriental alphabets

setlocale(LC_ALL, ".65001");
FILE* F=fopen("Example.ogg", "rb");

As I wrote above, the problem occurs when instead of "Example.ogg" I insert a file, for example, called "Exàmple.ogg" or "究 極 の 聖 戦 バ ト .ogg". With such examples, it is as if he cannot open the file. I searched the web for a long time for a solution, but found nothing.

Can you help me?

Thanks in advance