Spring HTC Evo 4G help? Please and thank you in advance!?

My dad gave me his HTC Evo 4G, and it's a lot nicer than the phone I did have, but the only thing is the power button doesn't work. My phone has only been able to turn on if the battery is placed back in, but it's never in sleep mode or anything like that because the button doesn't work. When I took it to sprint to switch the plan over to it, they couldn't do anything and they told me to go back in a few days when they "should have a part for it". In the mean time, is there an app (preferably free) that would help me change the key functions so the power button could be switched to the volume button or anything? I think my dad has already rooted the phone too, but we live in different states so it's hard for him to help me out on this one.
Any tips??