Import data from Word/Excel document (external) into Excel via Javascript addin.

Question

Good day,

I would like to confirm that you can not interact with an external Word or Excel document from an Excel Addin. My end goal is to extract and import tables from word and Excel into a consolidated Excel sheet via a JavaScript Addin.
A remark was made on Stack Overflow, but I would like to confirm this answer,
creating-word-document-from-excel-add-in-with-office-js

Kind regards
Nicholas