Push Mechanic Help

So, I have a homebrew based on the Year Zero System that powers the Tales from the Loop, Mutant Year Zero, ALIEN RPG, and Forbidden Lands. One of the core mechanics is "pushed rolls". After seeing the result from a dice pool, you can reroll all dice that did not come up a success or failure.

I found this push mechanic https://www.fantasygrounds.com/forum...Lands-Mechanic

And I found the lua for the dice manager action, but I need help modifying and adding it for my needs. I was thinking an extension (the link above is not for FGU), but my lua understanding is very limited.

I would like to have a "PUSH" button on the desktop that rerolls the last roll in the chat window. Sounds simple enough...

thx