Hey there,
I’ve replaced those in the past (on completely other things, though) by either using pcb spacer tubes or 3d printing small tubes. For iso metric screws you can cut a thread into the tubes, for the normal thread forming screws you just need the right sized hole. Take the prepared tube, cut to length and epoxy it into the casing you want to fix. It helps to carefully and completely remove the old screw post with a dremel or something.
Doesn’t neccessarily have the strength of the original, but for most things it works great 
Edit: If it is a simple part, model and 3d print the whole part.