From Unity3d How to develop selection Mechanism for GearVR?

Hi all,

I am developing a VR app in Unity to be used in Samsung GearVR. As you know, in the VR 360 home or any menu selection, we can use touchpad to select the menu. There's also a light, based on our head movement it also moves, with this help we can locate the menu or button(like rollover) and using touchpad we can make a click.

Same thing, How can I implement it for my own unity app. Like, If I use the point light to locate on my button or menu, the located button or menu or any object in the app should act for rollover, or I do some actions based on that.

Could you please help me?? Is there already some mechanism to do it in GearVR/Unity? or we need to do manually in scripting??

Thanks

Jeeva