What exactly do you want the system to do for you, and what specifically do you want the CA to do in that system?
Those will determine whether you can use the CA3 for that purpose.
The CA itself can be used with "any" controller system, if you use the SA model or if you get the standalone shunt to install between the battery and controller for your existing CA3 model, so that you can power the CA and monitor battery information.
If you want the CA to do more than that, then you'll need to make a cable that goes from the CA plug for the throttle output to the BBSHD plug for the throttle input. Then you can get or modify a throttle to plug into the CA plug for throttle input.
If you want something else, you'll need to specify what that is in detail.