Help! Motorized Throttle control in AP Mode?

Hello to All!Has anyone built or have a throttle quadrant that's motorized. I am looking for info on how that's done.Basically, Here's what I am after...When switching to autopilot mode, I want the throttle to move up/down in sync with the AP controls in the simulator. So when it's disengaged, moving the throttle up/down manually changes the response (i.e. speed), smoothly.Thanks.Sean W.