AFAIK it's not possible. a light cone will only move with the hull, never with the turret, even if the light(cone) is part of the otochlaven selection. i remember someone having tried it without success. the same should apply for the hatch selection which again is part of the otochlaven selection.
i think the game engine simply cannot handle it. remember that the light cone of the standard static m2 does not rotate with the gun, too.
a secondary turret script would solve that but that seems far away; maybe ArmA will solve it, maybe we have to wait until thegameformallyknownasofp2 :/