How to change the inputgrip coordinate without change the bounds?

i am doing custom attributs for ghcomponent UI
and done some change in gripper,some move:
I would like to change the x coordinate of inputgrip,but it seem need to override the Inputgrip property in gh_attribute.
then i try to overide the inputgrip in “component attribute”,but it doesnot take effects,i suppose i had to override inputgrip in “param attribute”,i try a lot,but i seems too difficult to do this.
Have you has some idea?thank you!