Trimmed surface and truss creation

Hello everyone,

So I am having some troubles with creating a space truss. I am trying to use the lung box component by but I want to apply the component to generate a spacial truss. However, if I create the surface from the curves I want the squares overlap the surface limit like this:

If I understood it right my problem is with how the surface is composed: I made a random surface in Autocad and I can only turn it into a trimmed surface. Any ideas how to solve this? or how to compose the surface as an untrimmed surface?

( the surface is composee by more than 4 curves so I cant create it from 4 curves with the surface from 2, 3 4 edge points

For that shape you are better off using the topology of a mesh. Look into Kangaroo + Mesh Machine.