How to shift Oculus hand avatar?

Hi , i am new to unity. I am using unity VR with oculus touch controllers to design my experiment. I want my hand avatar to be shifted 15 centimeters with respect to my actual hand. It can be achieved by just changing the transforms of local avatar and by shifted the sphere collider attached to lefthand anchor. But when i grab a virtual object with my virtual hand it always seem to work in previous co ordinated and not in the shifted position. Should i change something in the ovrgrabber script? can anyone suggest me the solution?