Like the dude above there is technically impossible. Unless you are an advanced coder who knows how to make there own software. Which I doubt you are. If you really want to make a mod I would look here for help http://www.minecraftforum.net/forum/140-modification-development/ or go into an online chat room and ask for help. But if you have never actually coded with java or any other launguage then I would advise not trying to learn how or even without trying to download something which will like I said be impossible.