Global/Master Template

Hi all!

I've got 400 or so letter templates written in Word.

Every so often my office change the header, footers, font & macro of
all of these. It would be a mamoth task to do manually.
I wrote a macro which opened each one in turn but that takes a while to
run as well.

Is there anyway that we can set up a master/global template which each
of these will use and therefore i only have to change the relavent bits
in only one document and not 400+.

Also if it is possible how can i get all 400 to use this document.

Hope somone can help. I really dont want to do this manually!

Thanks in advance!