Do you mean the small "control surfaces" on the main control surfaces? If so, those are the trim tabs. You deflect the trim tab the opposite direction you want the control surface to go to correct for the airplane not wanting to fly straight. The little tab puts pressure on the larger surface and it deflects the way you wanted it to go.

You could make them functional... but it would be a heck of a control linkage nightmare to do it. The only way I could think of is using the 1/32 wire cable in a sheath type pushrod, normally used for 1/2A and gliders. this stuff could still work for the little trim tab when the main control surface was deflected. There would be very little point to doing it though... We trim with fine adjustments of the main control surfaces on the models.