> I'm aware of MIDI mapping, my question was about the possibility to make a stand alone sysnthesizer (with keyboard and knobs) in which the necessary controls

> I'm aware of MIDI mapping, my question was about the possibility to make a stand alone sysnthesizer (with keyboard and knobs) in which the necessary controls would be read from analog inputs while still displaying them on the screen as if they were changed with the mouse, which is not easy to do when playing live. I see, I understood the opposite way! But yeah, what you are describing also exists! Many (high-end) mixers have motorized faders, also using MIDI if I remember correctly, so you can change the fader in your DAW and it's represented in meat space.