Is the point of this request
(a) to stop the user from clicking, or
(b) to allow the user to click while not being able to move the mouse, or
(c) to stop both moving and clicking?
Even if it's not possible, you might be satisfied with a macro that, whenever the user moves the mouse, fills the screen with a big warning to not move the mouse, like this warning:
I haven't actually give up on the idea of stopping the mouse. I'm still researching that, but I suspect you might like a warning macro just as much. If you are happy with a warning, I can write that up for you. In fact, it looks so fun I'm going to write it up whether you want it or not, and I'll post it in the Macros forum on this website.