Moving a lofted surface along the z axis

Hi,

I'm a new user of grasshopper and am having a very basic problem but for the life of me cannot figure out how to solve. I've created a lofted surface in GH using offset curves and lofting them together, my goal is to then use this lofted surface to boolean difference cut out of a solid model I created. I need to boolean the top part of the model but for some reason can't find a way to reposition my lofted shape up or down within the Z axis.

I am able to position it around the x axis as I have a slider connected to the X part of my Point Vector node but the Z part is being used to generate the shape of my curve. I have tried attaching vector direction nodes to different parts of it but cannot seem to get it to work. Any ideas as to what I am doing wrong here?

Attached images of my setup.