I need help with my table's spellcasting system

Hello, and thank you for clicking on this post. You sir, are a gentleman and a scholar! The thing is, my group uses the mana system (AKA the "spell points" system, which is an optional rule from the Dungeon Master's Guide). And currently, each player has to click the "cast this spell" button first, and then click a macro button that spends the correct amount of mana for a spell of that particular level. But isn't there some way, given this incredible wealth of API scripts, to have the casting of the actual spell automatically trigger the macro that spends the mana? Or, for that matter, any conceivable way to both cast the spell and spend the mana, with just one click? Respectfully, and with thanks, -Ronnie

I don't use that optional rule but I purposely seperate the slot usage in 5e from casting of the spell because sometimes a double click screws up the target token system and sometimes players click a button to see the spells info that also "casts the spell".  I'd much rather have the finalizing stuff seperate as much as possible.