You need an actuator that takes a proportional input signal. 0-10vdc is common. You'll just need a 24vac to 10vdc power supply for the manual potentiometer.

https://www.supplyhouse.com/Johnson-Controls-M9104-GGA-3S-DC-0-2-10V-Non-Spring-Return-Actuator-w-Screw-Terminals-35-lb-in

https://cerpangha.com/products/s963b-1136-honeywell-manual-potentiometer-270a

I'm not familiar with that hardware, but unless there is an off the shelf option you are related to engineering it yourself. There would need to be a stepper in there you can control directly, and a way of programming the controller to know how many steps to take.

I know those kind of motorized vents are used in commercial HVAC. (Here’s a white paper on a stepper motor for one https://www.portescap.com/en/newsroom/whitepapers/2021/10/customized-and-reliable-stepper-motors-for-damper-applications )

A stepper would be the easiest thing because if you know it takes 10 steps to fully open from fully closed, you could keep track of how many steps you have sent each direction in Home Assistant and be able to display the current status. 

If you want a knob on the wall that controls this, I think somewhere behind it you are still going to need a control system that translates wall switch inputs into stepping logic. Home Assistant would be able to do that easily.