I did some digging around on the boards and it would seem having a "button" for merely copying text into the clipboard is pretty tough. I would however love to see this implemented in the functionality for the button field added under actions. See attached image to see where I mean.
My specific use case is that I built a calculator for Day Trading, and I wrote a formula that generates my trades that I can just copy/paste into my trading platform. It would be really nice to be able to get my trades on my clipboard in a single click vs having to click-drag a part of the page on my interface, copy, and then paste.
Basically for the action all you'd have to do is specify a field, and when the button is clicked its contents are copied onto the clipboard.