There is no command to do draw an ellipse - however my guess is that an imported Ellipse object has properties and that an ellipse can be incorporated in a block - so you could create an Ellipse in a VCL file and then drag and drop it into the project and then edit its properties to move / scale / rotate it or you could create a block and then Place / scale / rotate it.
I have checked and there is no create ellipse command.
Out of interest, what is the use case for drawing an ellipse - is it pipes in cross sections or profiles or similar or something else entirely? Let me know. This is likely a relatively small / easy command to write as a "Stocking Filler" for the developers when they get a spare couple of hours with nothing better to do.
Typically - I cannot find a DWG with an Ellipse object in it (at least the first 8 files I have checked did not have an Ellipse - so if you have an Ellipse in a CAD file or if someone has Civil 3D / AutoCAD - could you draw me an Ellipse and export it as a DWG file and send it over for me to play with (alan.sharp@rockpilesolutions.com)
Thanks
Alan