How to make my data pack configurable?

I made quite a simple data pack that will ban a player from a server if they die outside a 200 by 200 block area centered around 0,0. I want the data pack to be more configurable however, where people can change the location where the area is centered around by using a command in game. I also would like to be able to easily change how big the safe zone is, however this is not as important. Does anyone know how to do this?