I had a leak in a lead wastepipe and managed to find the crack buried a foot deep in a concrete wall. I had to remove the cracked section of pipe but left an inch of exposed end free - although it's not in an easy to reach place. This pipe also joins onto the stack about a foot deeper but I'd have to remove a concrete balcony to get to it. Is there any way to join into this exposed lead pipe end with a plastic pipe? Please help as I really don't want to remove my concrete balcony or the rest of the wall!