Import PDFs and DOCs from content

Hello, I am importing data from an old (non-WP) site, from a CSV I’ve put together. The post contents refer to a lot of internal images, PDFs and other documents.

I could get the images by ticking “Scan through post content and import images wrapped in <img> tags”. But is there a way of importing other types of documents into the media gallery?

Essentially, I would like to import any .pdf, .docx etc file that’s referenced in the import, but only if they are internal documents from our server. So, I would like to import the documents that belong to our site (our-domain.com/file.pdf) but not documents that are linked to from other sites (not-our-domain.com/file.pdf.

Is this possible?

The alternative would be to get all documents from the old site, upload them to the server, add them to the media gallery with a plugin like https://ww.wp.xz.cn/plugins/add-from-server/ and then change all references to documents in the CSV before import.