It's better if you repair it, or you can maybe try try to get some liquid metal paste and put that in the hole, then put the screw in. when it's dry you can unscrew the screw and put the backplate on again. don't know if this works, but you can always try.

does the screw got any grip in there? or is it so loose it falls out?
when it's got any grip at all, you can try tapping new threads in the screwhole.