Hi Tim,
Thank you very much for the idea. Actually I solved the problem exactly in the same way you proposed. I wanted ORCAD format not directly to use it for ORCAD but to import into Altium polygones (Altium has a huge problem with import of polygones, simply there is no such possibility to make it from DXF). So I used the Altium ASCI format to generate directly the files and now everything works perfectly well. Now I can generate polygones, fills, nets, pads and tracks directly in ALtium format.