As the questioner behind that post, I can vouch for the AppleScript method. You should be able to hack it together with a little hunting on the forum, but if you’re having trouble I can dig up the shortcut I built after posting that thread. It reads the contents of a specific cell from a given sheet, so it probably does what you’re looking for.
As for renaming the file, my approach is usually to handle everything I can in Shortcuts and farm tasks out to AppleScript only when I need to. I would use the “return <variable>” at the end of an AppleScript action to feed the data back into a shortcut, and then use Shortcuts to set the name of the file.