I just made a model of a full extension bi-directional heavy duty industrial slide. I need to insert mates that allow me to make it extend 2000mm in both directions. I can easily do this in one direction, but not two. In order to have this accurately represent the way this slide works in my assembly, I need to leave 200 mm of the slide embedded in the beam when it extends.

What is the best way to do this?

I have attached my assembly and the parts that make it up.