Induced charge on a surface by a charged object at different relative positions

Hello,

I am new in COMSOL and I was wondering if anyone could five me any idea. I want to simulate the evolution of the induced charge on a surface as the relative position to a charged object varies, this variation must be parametrized by the user and not due to the electrostatic effects. My first idea was to parametrize the position of one object as a function of time but i couldn't. Is possible to do it in any other way? Thank you very much in advance!

Gerard