You might be able to export AutoCAD drawing to HP Graphics Language using the export function.
Convert AutoCAD drawing to HP Graphics Language plotter file.
We found 3 software records in the database related to .dwg to .plt file format conversion.
Microsoft Windows software - convert dwg to plt on Windows
Leading 2D and 3D CAD development software from Autodesk
Convert from dwg file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned dwg to plt. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A set of applications used by professional graphic designers
A free graphics editor