1/4-20 screw extensions

I was cleaning out the vent fan intake in my bathroom. When putting everything back together I broke off about 1/2" of the screw that fastens everything back together. The head of the screw is inside the fan assembly. I would have to remove the fan and take it apart to get at the screw head, something I don't really want to do.

Do they make 1/4-20 screw extensions? I need about 1/2" extension. I looked around the internet but was having trouble finding anything. Links would be greatly appreciated!!

Thanks,
Ken