If you would prefer to avoid VBA then I don't think you will get close to a
"one-click" solution, and whatever you do it is likely to cause a certain
amount of confusion for the users. Two possibilities depending on what the
users are capable of and willing to cope with:
a. Create an Excel data source as you suggest and use it as a mail merge
data source. However, there is no need to introduce an extra program - you
can create a Word document containing a two-row table. The first row
contains column (field)names. The user types the data into the second row.
Use that document as the data source for a merge. The user should be able to
open each document, preview the document, and either print, merge to a new
document, save etc. If they need to save reliable copies of the things they
are printing/producing, they must either merge to a new document or unlink
all the field codes by selecting those parts of the document that contain
fields and using ctrl-shift-F9.  An advantage of this approach is that
/some/ formatting can get through to the including documents if that is
desirable, by using { REF } fields in the mail merge main document instead
of { MERGEFIELD } fields
b. create a Word document with one SET field for each field, e.g.

{ SET mytextfielda ""
}{ SET mynumericfieldb
}

(NB, all the {} are the special field code braces that you can insert using
ctrl-F9)

Select the entire document apart from the last paragraph mark and use
Insert|Bookmark to create a bookmark called mydocbody.

The user maintaining the data would need to
 a. open the document
 b. display the fields (Alt-F9)
 c. overtype existing values with new ones
 d. select the document (ctrl-A)
 e. Re-execute the fields (F9)
 f. close the document (optionally at this point)

In the including documents, use Insert|File to insert the file as a link,
specifiying the bookmark as the range. You should end up with an INCLUDETEXT
field such as

{  INCLUDETEXT "C:\\myicludedfile\\mydata.doc""  mydocbody }

Use { REF } fields to reference the included { SET } fields.

The user maintaining the 6 including documents would need to open each
document, select any areas of the document that contain references to the
SET fields (ctrl-A if it's just the document body, but more effort required
if there are fields in headers/footers etc.), and press F9.

You may need to uncheck Word Tools|Options|General|Web options|Files|Update
links on save to stop the INCLUDETEXT from going wrong.

Personally I suspect (a) would be the easier of those two in the end.

Peter Jamieson