Port it as a plug in to old versions of excel as first class citizens on release. There's been far too much, "here's a feature people will use so you're going

Port it as a plug in to old versions of excel as first class citizens on release. There's been far too much, "here's a feature people will use so you're going to have to pay us yet again to open spreadsheets" in the history of excel. It's shit. It's awful. Don't do it. Using rich customers desires to extract money from those who neither need nor want the new feature is a crook's game. If microsoft aren't evil don't do it.