Add date in a Edit-Protected File

I would like to create what is specified bellow, but have no clue how to do it.

TL;DR "u have this Checkbox Checked, so add a date to it" in a Edit protected Word file

The problem is like this:

I need to create a template for my use, but I give this document to others, so I need to write protect it, so they only do, what I allow them to do.

Now, we know they cant add anything to the document, that isnt already in it. BUT I have a multiple checkbox table, where they specify if they have that (what is specified) and I want, for all Checked boxes to add a date untill which they have that. if its not checked, it doesnt show the date box. 

I would apreciate any recommendations.