There may be a simpler approach, pot inputs can usually be substituted for a varying voltage between the common terminal and the pot slider input, you would have to check the voltage across the outer ends of the pot to find the max voltage seen at the slider input.
There is a possibility to use an analogue input direct, or if the voltage required is larger than the analogue signal available, or it is not feasible to use a non-isolated approach, then maybe a OPTO IC such as H11F1 could be put to use.
This OPTO accepts a varying voltage and the output simulates a varying resistance depending on voltage in.
The input to the Opto may load the analogue signal up so a unity gain op amp may have to be used together with the H11F1.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.