Placeholders/Tags

It would be great if we could upload a PDF/Excel/Word document. We could then add a calculated value from a report (using tags/placeholder similar to how you do mailmerge. As a final step, be capable of downloading the PDF/word file back with the added values. There is a high demand in printing documents with a specific layour/style that can only be achieved with the use of external programs.... we only need the calculated values from Power BI.