The folder the DXF file is stored is defined by the cuttingpath in the norms\cvar\cam.conf (Production > Plate Cutting Data > DXF Output > Settings > Directory). Note that its value is appended to the productionpath in norms\lvar\cam.conf (Production > General > Output Directory) to form the final folder name.
The file name for the resulting DXF file is determined by the dxffilename setting in %ncgnorms%\cam.conf (Production > Plate Cutting Data > DXF Output > Settings > Filename).