Change variable with macros

Hi, I creat a rpg were every action have an impact on the characters stats (such as attacking cost health) and I wanted to know how to chage a varible (like healh) with a macro ? For exemple, I want that when the player clic on the abilitie, it automaticaly roll the dice (that I know how to do) and change the life and mana of the player's hero. I know my game will finaly look more like a video game than a rpj, but it can help for the free flow... (Don't care about my English plz...) thx

This is doable with the API, but not with regular macros. The API requires that the campaign creator has a Mentor subscription.

I know you can do that with API, you can do everything with API, but I don't want to pay every month just to do that... Is there an other way ?

There is not facility for automation in the macro system, only calculation. Automation is purely the prevue of the API, as Brian has mentioned.