Netcad software boasts a broad range of file format support and can export its own drawings (including .ncz files) to various raster, vector, GIS, CAD and other related file formats. In the case of DWG for, Netcad supports older format based on features of DGN-V8/DWG-DXF (2006) and thus should be capable of ncz to dwg conversion support.
Unfortunately, we do not know about any other software that can convert to ncz to dwg, which means it is most likely impossible to do so without Netcad.
Updated: June 16, 2023