Dear bacchus,
To know about exporting formats, you can enter the command EXPORT in command line and open the list "Files of type" in the dialog box. All accessible formats are listed there.
Some other exporting formats can be accessed using the SAVE command.
Since Autocad uses the ACIS kernel, I doubt you will ever see the ability to export Parasolid files. You may be able to pull an ACIS file from Autocad into Solidworks and export it as Parasolid though.
I have a AutoCad 2002 drawing that I want to export to an engraving firm's engraver. I draw the original file in the standard *.dwg format and then save as a *.dxf file so that can use it(or change it to their format). The trouble is the fonts are not coming out right on their graphostyle machine. (ie no word wrap/double lines/layers appearing that were not on my drawing.)
They suggested using the Export facility but I tried to use the DXX format (but not with any success). Has any body used this format or had this problem before?