I've experimented adding coconut milk to white rice and my result was that it has never given the rice any worth while noticeable improvement. It just doesn't seem to turn white rice into coconut rice. To accomplish the latter, I think it would be better to add unsweetened dried coconut. (I haven't closed out this experiment yet but I have nothing worth sharing at the present.)
My favorite uses for coconut milk are various types of Thai curries (including chicken halves braised in coconut milk, curry spices, etc.), and in making dipping sauces.