Drive Mail Merge from excel Macros (using Embedded Docx Templates)

In Word mail merge, the usual procedure is to create a 'main' document that contains the path to the datasource and the appropriate merge fields. There is a mail merge wizard to help you through the steps. This is then saved, so that whenever the necessary, the document can be opened and a fresh  set of letters, emails or faxes can be produced.

This code anticipates this, though I notice that the embedded documents aren't actually set up as merge documents,  so the code aborts when the MailMerge bit is reached.
Sub DoMerge()
    Dim wdApp As Word.Application
    Dim wdMainDoc As Word.Document
    Dim wdResultsDoc As Word.Document
    ActiveWorkbook.Worksheets(1).OLEObjects(1).Activate
    Set wdMainDoc = ActiveWorkbook.Worksheets(1).OLEObjects(1).Object
    Set wdApp = wdMainDoc.Application
   
    With wdMainDoc.MailMerge
        .Destination = wdSendToNewDocument
        .Execute
    End With
    wdMainDoc.Close wdDoNotSaveChanges
End Sub

:) yes I know the usual method is start with Word, then Excel as data source
that's why I'm asking if the reverse is feasible

Neither of the embedded docs in the sample are "setup" - it's conceptual

I want to operate this way as there will be several (simple) word templates, but only one (complex) workbook: the information will come from the workbook so the workflow is more logically controlled in the workbook. Plus I need to distribute this - it will be far easier if all parts are in one file instead of something like a zipped folder (although if that's the best route please tell me so).

You can assume the word templates would have merge tags in them, what I'm really after is:

how to 'unhook' the embedded document to file, then
get that file to start "mail merge"

this looks hopeful
http://stackoverflow.com/questions/1357121/executing-word-mail-merge

a new file - now one template has merge tags in it

I would like to achieve this with buttons if possible, each button must invoke a different embedded document

(double-clicking on a document instead might work perhaps, less desirable)
Make-Docs-From-Embedded-Template.xlsx

excellent, this is looking quite promising, just another dumb question or so:

The macros provided are doing fine so far - thanks you - I'd just like to know a wee bit more about referencing those embedded objects (see above)

follow on question if you are interested:
https://www.experts-exchange.com/questions/28128386/Mail-Merge-Generated-Document-How-to-keep-field-in-a-paragraph.html

Have to fine some method to 'name' these objects I suspect

even a list of them would be a good start

Regardless, thank you for the great start here - it's looking promising.