My kitten got hurt in the door. Both back feet might be broken!

Does anyone know what to do for a 4 week old orphaned kitten with both back legs broken? He has some spunk, but he is thin and can't walk. I have been feeding him milk and canned food since we found him, about a week ago but his mamma was hit by a car and we didn't find him for two days. Then, yesterday he was trying to get in when someone opened the door and he some how got caught! I am wondering if there is a power food I should give him to help him heal or if I should make a splint? I am maybe going to asks some friends who have the same size kittens right now if we could see if their mamma cat would take him for a while while he heals. Any suggestions or experiences? Tweet