AFAIK, there are no settings for Blender’s DXF export function - you basically take it as it is. If you must use that format, perhaps investigate (search for) other python export scripts which may produce more compatible output.
Alternately, look at your simulation program to see if there are any other formats which it may import. DXF has so many versions (due to Autodesk attempting to keep it proprietary) that it has become very unreliable as a conversion format (as you’ve experienced here.) Other, more reliable, more “open” standards are STL or VRML. Blender supports many proprietary formats, such as OBJ or 3DS, thru user scripts, which are good for this, too.
Your third option would be to find an intermediate application which will read blender output and give you the DXF formatted as you need it. 3DStudio should have a lot of potential for this, and AutoCAD may be an option as well, if you own these. Otherwise google will be your friend.
Hope this helps somewhat… good luck!
(BTW, what is the simulation software you’re using?)