Is there a code that prevents the user from activating a particular running application ?

So let's say MS Word is running. I want to prevent Word from being activated either via the TaskBar, ALT + TAB , or any other way.

I have already been experimenting with some subclassing code to intercept the WM_ACTIVATEAPP but I 've had no luck so far.

Any working code anyone ?

Please no DLLs solutions as I am using VBA.

Thanks.