This function takes as its only parameter a window handle.
If that handle is nonzero, Windows simply stops updating the contents of that window on screen.
The following macro lines will, respectively, turn off screen updating and then turn it back on in a VBA macro.
The idea is to use the first line near the beginning of your macro, and then use the second line near the end.
This means that the Word screen can look like it has "gone crazy" while the macro is running.
One thing you may want to do with your macro to make it run faster and to prevent distracting flashes on the screen is to turn off screen updating while the macro is running.
If the handle is 0, Windows reenables screen updates to the locked window.