RC Transmitter Potentiometer

Wondering if anyone could give me some help please. I'm trying to understand the problem, let alone a solution.

What I want to do is control via RC a 24V DC motor and a linear actuator. On the remote control, I would like to build a In/Out button for the linear actuator, and a dial (numbered knob) for setting the speed of the DC motor.

Has anyone had any experience with something like this, and can give me some steps or resources to investigate? I can find a bunch of stuff about barstardising RC buttons for controlling the linear actuator - but am having trouble finding how to do a numbered knob for the DC motor control.

Thanks for any help.