To see what can be achieved with Word's Catalogue/Directory Mailmerge facility, check out my
Microsoft Word Catalogue/Directory Mailmerge Tutorial in the 'Sticky' thread at the top of this forum:
https://www.msofficeforums.com/mail-...-tutorial.html
The tutorial covers everything from list creation to the insertion & calculation of values in multi-record tables in letters. Do read the tutorial before trying to use the mailmerge document included with it.
Depending on what you're trying to achieve, the field coding can be complex. However, since the tutorial document includes working field codes for all of its examples, most of the hard work has already been done for you - you should be able to do little more than copy/paste the relevant field codes into your own mailmerge main document, substitute/insert your own field names and adjust the formatting to get the results you desire. For some worked examples, see the attachments to the posts at:
https://www.msofficeforums.com/mail-...html#post23345
https://www.msofficeforums.com/mail-...html#post30327
Another option you might consider would be to use a DATABASE field in a normal ‘letter’ mailmerge main document and a macro to drive the process. An outline of this approach can be found at:
https://answers.microsoft.com/en-us/...1-1996c14dca5d
Conversely, if you're using a relational database or, Excel workbook with a separate table with just a single instance of each of the grouping criteria, a DATABASE field in a normal ‘letter’ mailmerge main document could be used without the need for a macro. An outline of this approach can be found at:
https://answers.microsoft.com/en-us/...f-8642e46fa103
For some working examples, see:
https://www.msofficeforums.com/mail-...-multiple.html
https://www.msofficeforums.com/mail-...tml#post151706
https://www.excelforum.com/excel-gen...ml#post5110813
(the second of these uses a macro to apply some additional formatting).
The DATABASE field can even be used without recourse to a mailmerge. An example of such usage can be found at:
https://www.msofficeforums.com/mail-...html#post67097