I really want to know where to get an app or somthing like this

i jailbroke my itouch 2g 3.0 with redsn0w recently. i have found some good sound themes, but i desperately want to make my own custom sound theme. i want to be able to take an mp3, throw it in audacity, cut a clip i want for my lock sound out, save it as an mp3 or wav or w/e, open up a program, and make a theme where that is the sound i hear when i hit the lock button, or the sound i hear when i unlock it, or when i put it on the charger. there must be some way to do this. its not like i havent found sound-only themes on cydia, or even full themes with sounds. can some1 please tell me what i need to do it, how to, ect?