Reply To: Override page numbering on Pages panel?

The closest thing I can think of would be to set a section start at each page you wanted to label. Then in Numbering & Section Options add a section prefix (up to 8 characters). The prefix doesn’t have to appear on the document pages, but it can be added to the file name when you export separate PDFs for each page.

Or, if you don’t mind spending $80, ID Extras has a much more powerful/flexible solution. https://www.id-extras.com/products/extract-pages/