Change Factor Value from Logic Node Tree?

The “factor value” belongs to the Mix Shader node into Shader Nodes, but is there a way to modify it from the Logic Node Tree ?

Have you got a try for example to set a driver and reuse it in one of your own node ?

For info : I tried to modify the Fac using the coord of an object that move as in the thereafter picture … nothing happens

(tested in Cycles Render/Object Mode/Rendered: moving the cube is perfect as the color change …)