animateing textures in the blender game engine

ok so i got a charecter i want to animate his eyes (heres how there built i textured them to the face and the inside of the eye is a alpha and there is a copy of the plane its textured to behind the face ) i want to be able to animate the texture int he eye to make it look like he is moveing his eye the iris and eylid are 2 diffrent textures i know u can do this becuase i got the ideah to rig an eye like the from the game the legand of zelda twilight princess anyone know how to do this ? :3 plz and thank u