Hi there CT, welcome!
I see everyone who posted has already got you covered but I recommend you should go to the Emulation section which has all the ROM hacking information you need to know.
And I herd u liek Nidoqueenz? What made you like this Pokemon cos it's an interesting one and I know Gary has one in the anime too.
Since you play on your Xbox 360, you should check out the Video Gaming subforum as well.
If you need to talk, feel free to VM me.
Have a great time and make some new friends!