Make Viewport, Bulleyes in a Tower

Hallo dear Comunity,
I´m a Student (an absulute Grasshoppernoob working on mac Rhino)) in BA3 have to construct a watch tower. The tower has to static systems, an inner sytem and an outer system.(Outerstystem:

) and the Surface on which are the Lines ( ) Innersystem( ) and the Surface on shich are the Lines(. Now i want so pusch the Line beside, so the tower get some Viewports throug the constuktion( )
I´ll Tried it with an attractor point but the points are push away from the surfaces. After transfering the points back to the Surface some of the constuctionlines are cossing other so the painting is not pricise.
In addition the rhino file and the grasshopper file.
grasshopper dreieck.3dm (3.1 MB) (90.8 KB)