how to change world position on material trough a controller input?

Hello, I am working on a VR project with the HTC Vive and I used this Tutorial: to make a nice warping affect but i have a problem

I want the affect to occur on the controllers after I do a certain combination(trigger button and the movement of the controllers) and when I do that combination I want the absolute world position inside the material to change to the location the controllers were at when they started the combination(pressed the trigger button) and then after the movement is over to change the absolute world position to a fixed location again

here is the material structure and the collapse location is responsible for the location in witch the object that is using this material will start to warp:

I have absolutely no idea how to change the material location like that any help will be deeply appreciated

Thank you in advance

i would love to know what you think even if you think its impossible to do

yes its impossible to do