Welcome to the PokeCommunity, Kakko! :) It's nice to see some ROM Hackers like you, and you're from Italy as well! I'm learning Italian in my own time, though it has been quite a while. xD
A ROM Hack of Diamond...in Italian... that's something I'd totally play. With that, I'll learn more of the language. ^_^ Though I haven't really played Diamond myself, so that's something new. (Only played Platinum). Be sure to check out the DS tools you may need in the Toolbox section of the Emulation section. Those tools over there will definitely help you out. And be sure to take advantage of the rest of the Emulation section as well, there are a lot of helpful tips and advice that will be very useful. :3
Be sure to read the rules, and I'll see ya around the forums then? Have fun!