Yes .....I it is possible....Only one constain is there.... that if you are using single turn POT thne you can have only some steps for the resistance control but if you are using multi-turn POT may be you will get fine control for resistance.... you can either couple directly or even with gear mechanisum
Then you should be able to get the control the using stepeer motor .....Only the part here is getting connection mechanically solid wiil be bit tuff .....