If you have existing ellipses to convert to 2D polylines, you can export the ellipses to DWF format, then reinsert into the drawing. First, set the PELLIPSE system variable to 1 and the PLINETYPE system variable to 0 (so polylines aren’t changed when they are placed in the drawing). Type Dxfout at the command line. In the Save As Type pull-down list, select AutoCAD R12/LT2 DXF (*.dxf). Go to the Tools menu in the Save Drawing As dialog box and select Options.
Caption: Select AutoCAD R12 DXF in the Files of Type pull-down list, then select Options from the Tools menu.
On the DXF Options tab, check the Select Objects box.
Captions: DXF Save As options. Check the Select Objects box to pick individual ellipses to save as DXF.
Click on Save, then select your ellipses. Press Enter when you’re done. Type Erase at the command line, select the ellipses, and press Enter to erase them. Type Ddinsert at the command line, then select your DXF file. Make sure the Specify On-screen to Insert the Block box is not checked. Select the Explode option, then click on OK.
Caption: Ddinsert dialog box.