Change ability score used to all weapon attacks

Not super familiar with Roll20 or macros, but I want to set something up where I can toggle on or off an ability that my character that where I can use CHA instead of STR or DEX for weapon attack rolls (if I use a BA to activate it). I've tried to look into how to do this using the global attack modifiers but I can't figure out how to replace the attack ability score. Any help is much appreciated <3

Which character sheet are you using? 

Sorry, forgot to mention this! We're using the Star Wars 5e sheet (I'm a player btw).

What are your scores in the relevant abilities? 

Strength mod is -2, Dexterity mod is 0, and Charisma mod is 5. I wonder if there's an easier way than just having numerical bonuses for each str-based weapons and dex-based weapons.

So for Strength weapons you need a +7, for Dex weapons you need a +5.  You could do a global query ?{Former modifier|Strength,+7|Dexterity,+5} Alternately you can have two global fields, checkmark the one that is appropriate when you attack.  Final option: make two attacks for each weapon. One with Strength/Dexterity (as appropriate), one with Charisma. 

I wanted to avoid setting up the second attacks, but ended up going that way. Thank you!