Hi @BinaryNumber , thanks for your suggesions, i have understood clearly how to proceed 🙂

Does it work only for mame or all systems with their own emulators?

Thanks again

@flaker38 Thank you. Everything worked out. Did according to your advice. Now I play like a real Nintendo 64!

@supernature2k
I am immensely grateful with you! I swear I made my research in the forum and I found many topics that talked about this, but none of them were conclusive (the ones I saw). I found one that I think was the one I needed but it was in french, I translated with google translator, but I wasn't much of a help.
I found difficult to find the main theme.xml (even with WinSCP) but I did it.
I am truly grateful, thanks! You all make a great job!

Thanks for the tips ! (sorry for the late reply, I just noticed that I was not watching the thread for some reason?)
Will try this and let you know