Operating a Blend Door Actuator without a microprocessor

I have a "Blend Door Actuator" from a 2008 Lincoln Towncar. It is a "Servo Motor System" consisting of a DC Motor, gearing, and a potentiometer that has a rotary output. Its position is indicated by the pot, which is fed +5Volts reference from the HVAC Controller. I would like a 'simple' way to build a 'black box' that will take the voltage Input from a Pot and cause the Motor to move the Output Shaft to requested position, that position based on the output of the Internal Pot. I want to use this in an antique Car to replace an 8 foot long steel cable that controls the Heater "Blend Door!" Any suggestions will be helpful! Thanks. Dale