I'm working on a macro and need to open a DXF file from within.

I've tried several OpenDoc variants and tried to shell out as well.  Any suggestions would be appreciated.

Background to the macro - all this is working fine - just missing the last piece

• Starting from a chosen view ( a flat pattern in practice) in a solidworks drawing, I add information to the sheet: File name, date, material thickness, Kfactor, Scale of the drawing  & current user
  
• I then save out the sheet as a DXF.  The file I save out to does exist (checked by debug.print strFileName, then paste that into a command line - which does opens the DXF in autocad)
  
• Now I want to open the DXF file from the macro for the last steps we take in preparing DXF files for our shop. 
  

Thanks for any help