You might try your local hardware store for a screw. It's doubtful that you'll find the correct one, but you'll probably find one that will thread into it gently and hold things together w/o harming anything. Just bring your camera in there w/ you. The folks who work in the stores, in my experience, are always grateful to see something out of the ordinary, especially a camera like yours, and will be happy to help you. They generally know where everything in the store in too, saving you some time. If you're lucky you can find a brass or plastic screw that will sort of thread it's way in there w/o harming the harder piece you're screwing it into. Just put it in there tight enough to hold it together.