The  CREATE_DIRECTORY  procedure  creates  a  new  directory  or
  subdirectory.

  Syntax:

     CREATE_DIRECTORY( file_name [, error_return] )

  The  'file_name'  parameter  must  be  a  directory   name   and
  optionally  can  contain  a  device  name.   The  'error_return'
  parameter is optional, and will return an error recovery code if
  specified.