VMS Help DCE_IDL, ARGUMENTS, -cc_cmd  *Conan The Librarian (sorry for the slow response - running on an old VAX)

   -cc_cmd 'command_line'

   Invokes the C compiler and compiler options you specify in the
   'command_line' argument rather than the default C compiler and
   compiler options.  When used with the -lang cxx option, the -cc_cmd
   option specifies the C++ compiler.