The 'template' you're describing is a mailmerge main document. You cannot apply editing restrictions to such a document.



You could apply a password for modifying the file, setting the 'read-only recommended' property, or apply the Windows read-only attribute to the file, but all of those only prevent an unauthorised user saving any changes they make; it does not prevent the user making changes, then running a mailmerge with those changes in place.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]