not trying to be a buster, but i'm completely lost, the treaded bolt the screw screws into? do you mean nut or stud or what? cant screw a screw onto a bolt, should screw a nut on a stud or bolt, i cant see the pictures either, if it is the strut bar bolt i'm thinking of it should be a threaded stud sticking up from outer fender coming in through the inner fender, if it broke off and you can see the head from the inner fender but cant drive it out, the head of the stud is probably tack welded to the inner fender, you can grind it off if so and replace with another bolt, or grind it flat then tack a new stud or bolt to the fender well. if it is a nut that is tacked on top side with bolt broke off in it you can drill it out and re tap it.