Can a Reroll Expression push a Query to decide whether or not it rerolls?

I'm not sure if this is something that can be automated without API, but the goal here is essentially to roll 2d20kh1, and if the kept result is a 20, the macro gives you a yes/no query asking if you want to spend a resource to reroll that same expression or keep the original result. While also tracking how many times this happens (how many resources are spent after multiple natural 20s) as the damage multiplier will be increased by this number. I don't know where to even start in setting up a macro like that, so any suggestions are welcome!

Regular macros can't do conditionals, it can be done with an API. You could have it throw a button [Crit?] on every roll and just ignore it if conditions are not met. Counting would require an API. Sorry to be the bearer of bad tidings, but those things are not for us mortals, that is Aaron territory.

No worries, I like the button idea! It's only an effect one character has, so making a single button will be faster than coming up with a script. Maybe I could have it use the Ammo script to keep count, too.