Are you building a compiler for VM? If so you might want to look at the two assembler routines on the Fortran 191 disk which provide the interface between CMS and the OS Fortran compiler.
See my reply to Mark Stevens regarding RUNPARMS and XRUNPARM... :-)
Also, for VM/SP and above, you should be able to use the OSRUN command that is built-in to VM/SP and above to invoke your compiler with an OS style parameter list.