It sounds like your linear actuator is operated like a brushed DC gearmotor. If that is the case, the maestro cannot directly control it; you will need a motor controller that can accept hobby RC servos from the Maestro. For example, our Simple Motor Controllers can accept hobby RC signals.
If there is not a particular reason to use the Maestro over another controller; it might make more sense to use a microcontroller like an Arduino and a motor driver. If you give more details about your application, I might have more advice.