V8i SS2 - Excavation with two slopes

I think I may have a case of the Monday's here.  I am looking to make an excavation template with two different slopes in InRoads.  I want to start from an excavation bottom shape and have the template find the existing surface.  The point at which the slope changes in the template is at a set distance below the existing surface.  What would be the easiest way to set up this template?

Thanks,
Joe