The only way to control power from the trigger is to have a system that offers communication between the camera trigger and the remote trigger that includes the flash units.
That, by definition, means a vendor specific or at least technology specific system.
As mentioned, a lot depends on the lights you currently own.
Simply put, first look to the manufacturer of your lights to see if they have a trigger system that supports your camera.
Looking at your signature, it appears that you have bought into the Canon speedlite system. The 600RT and its supporting triggers are the best place to start.