Yes.

It is called Mail Merge.

I am a lawyer. I routinely use mail merge to prepare legal documents (one at a time, not a mass mailing). Each item to be inserted is in a separate column in the Excel spreadsheet. That column has a title in the first row. The title becomes the name of the merge field that is inserted in the document.

Virtually all of my rough drafts are started this way. On about a quarter of the documents, no revision is needed after the merge.

You would be able to get more information about mail merge problems in the mail merge forum.

Once you have this set up, you should be able to get the client to put the information into a spreadsheet with the columns already appropriately labeled.