I have a unique (to me at least) requirement that I sense could be solved with Word but could use some hints (if it is possible)...

I will have a document that will need to be updated from time-to-time. That is, the SAME document will have more information added to it EACH TIME the document is 'opened'.

This added information will be added 'automatically' through a VFP interface. Essentially there will be a button on my form to access the subject document and before it is presented the fields will be filled (those for which values exist at this time).
The user will be able to annotate the document in specific areas and then save the document, and the next person who uses the button to access the document will see the LATEST information - fields auto-added plus most recent annotations.

I don't see a Mailmerge working here, but of course I could be wrong.

Can someone please suggest a good and proper way to accomplish this using Word?

Many thanks