Grasshopper Archicad Surface from wall?

Is it possible to extract a surface from an imported (archicad) wall?

I need the curved surface to divide it and use it for panneling.

Unfortunately the Archicad plugin only gives us access to the faces. Worse, we can’t deconstruct the profile into a usable shape.
You can create a new extruded surface from the existing wall as the base and make a new “wall profile” to use as an extrusion curve. Only then you will be able to work on it.
Another option is to extract the points from the wall and make a new nurbs surface from them.