There is no way to "force" the other users to use paste special. Without
knowing the layout of your sheets and what, why and how they work and
why you are copying and pastings I can't give you any specific advice.
But her is some general stuff.
You could put a text box on your sheets with an explaination of why
they should use paste special and how to use it.
You could reformat the cell you copy from to match the format of the
cells your pasting to.
If you are coping the exact same range of cells and pasting to the
exact same range of cells every time, you could use a macro.
HTH