Revit: Lock Reference Point to curve (as a guide)

[jpyeatt]

I have a curve that rises vertically (in Z), moving in X,Y as the height changes.

I need to lock a reference point to this curve. (Point X,Y will always match the curve)

I then need to make the point's Z-value into a parameter. The idea here is that the curve acts as a guide/path for the X/Y locations. Z (height) will change. I don't want to physically move the point, but would like it tied to a value. Can anyone help me setup this relationship?

This is for a Conceptual Massing Model. One point will be associated with each 'end' curve of the mass. This will eventually be used to clip the top of the model...

Thanks!