This is an Excel forum and you'l probably get good help on hiding things in
Excel in here, but not a lot for Word and/or PowerPoint.
For Word, you're going to want to set the Font.Hidden property to TRUE in
VBA code. You can record a macro to do that. I suspect that you want to do
this at some particular time or based on some action and there are very few
events to choose from in Word.
For the Excel side, if you'd explain what it is you want to hide and when
you want to hide it, that will help here. Again, you could record a macro to
do this and use that if you just want to hide the information when you decide
it needs to be hidden. But if you want it to be hidden under special
circumstances (as when data in some worksheet meets some condition) then we
need to know what those circumstances are.