Export does exist, and the citation does travel with the cell as a cell comment (should show up as a red triangle in the corner of the cell in Excel). This feature does need more testing.

As an alternative, I can provide a checkbox on export to have a "sources" sheet created in the workbook with references back to the cell if that works better.

If you do decide to use it, I'm happy to work with you to make sure the export works reliably. I haven't had a good test user for this yet.