I am facing the same issue of trying to control the copy and paste problem.
There is just no solution to this.

Rather, I have yet to find a solution to stop the users from changing the formatting of a cell.

I have conditional formatting included in the cells and once the copy and paste thing happened, my whole formatting is gone.

And no macro allowed. I saw some postings in the Internet stating that macro has its limitation also.

It appears to me that this is an unresolved issue for Excel.