Motorized rotary switch
Consider using a motorised rotary pot, connected to an ADC read by the MCU that controls it, which also controls solid state analog switches (or relays as appropriate). (If it's merely input to a micro, these switches are unnecessary; I mention them in case you need real switching too)

You won't get the click detent of a rotary switch, but you can simulate that by driving the motor. 

As you turn it, the ADC reading increases : when it crosses 50 increasing, drive the motor (at low torque = low current) to 100. If the user lets go at 125 it springs back to 100; if at 175 it clicks forward to 200. Experiment with torque and deadbands (90 to 110 count as 100) to get the feel you want without motors chattering.

Number of switch positions is obviously software configurable.