If not, this tutorial will be pleasantly surprising for you. In this article, we are going to show you how you can convert a CSV file to an Excel workbook. For that, we will be using a VBScript.

If they're COM .dll's, you can call them from script no problem. If they're Excel add-ins, I think you're going to be out of luck. Sounds like you're on the right track though.

Within Power Automate, it has been possible to run scripts in Excel using the Run Script actions. Did you know that the is a Run Scripts from SharePoint library action too?