Adding documents to a Word document is always problematic. You can end up with formatting that is very surprising unless it is planned very carefully with a small selection of documents.

If you are sending by email, how about adding the selected documents as attachments to the email?

Note, I do not have the skill to do either. I'm just looking at it from the perspective of how I would do it.

Also note that any solution is going to require macros, and you likely have no control over whether the user will allow macros to run.