Macro for adding result of d20 roll to a pool/resource each roll

Hi All!, I'm trying to create a macro for a player that basically adds the result of a d20 to a pool each time. This is being used to basically track a PMC learning a skill so when the eventually "study" the book enough, and get to 100 total, they will have learned the skill proficiency.  Anyone have any idea how to go about this? Ideally the roll would trigger a question asking "add to pool?" before doing it because the player in question often rolls by mistake. 

This would require an API Script, probably ChatSetAttr.  How I would do this is by putting a Chat Menu button in the macro instead of a query. Then the user presses that button.  From there the button triggers another Ability macro.  That ability macro asks which attribute to add the d20 to and then uses ChatSetAttr to add to the attribute. 

Thanks for your reply! Much appreciated. I've never made one from scratch before but I'll give it a shot!

If you run into any issues feel free to ask for help. 

Thanks! Ill let you know what I come up with!