I have this same issue on my Squier VM Jazz, and so far it's not a problem screwing it right into the pickguard itself. The pickguard appears to be quite adequate in holding the cover tightly. Shouldn't be a problem with the hole stripping out, unless you are taking off the cover every other day. however, SurferJoe46 solved it by screwing in a piece of appropriately sized wood (looked like half a wooden thumb rest) into the wiring rout cavity in the right spot.
Oh, and patience is a virtue, my friend.
You can call me ...Cliff.
"If I could walk that way, I wouldn't need the talcum powder."