Enables you to specify a user program as a precompiler for BMS files. 
Syntax:
>>--/----PCOMP=userprog-------------><
Parameters:
- 
userprog
- The user program to be used as a precompiler.
Example:
working-storage section.
       01.
           05 install-flag       pic x comp-x.
           05 install-params.
               10 exit-proc-ptr  usage procedure-pointer.
               10                pic x.
       01 p-exit-block.
           03 p-block-size       pic x(4) comp-5 value 16.
           03 p-return-code      pic x(4) comp-5.
           03 p-rts-error        pic x(4) comp-5.
           03 p-exit-flags       pic x(4) comp-5.
       linkage section.
       01 source-file            pic x(256).
       procedure division using source-file.
           display source-file
      * On exit the file specified in source-file is the one
      * the compiler will actually compile
       	   move "EMPLOY.BMS" to source-file
           set exit-proc-ptr to entry "exitproc"
           move 0 to install-flag
           call "CBL_EXIT_PROC" using install-flag
                                       install-params
           end-call
      * Zero means continue, non-zero abort
	   move 0 to return-code 
           exit program
           .
       exitproc section.
       entry "exitproc".
           display "in exit proc"
           call "CBL_GET_EXIT_INFO" using     p-exit-block
           exit program
           .
Comments:
The user program should return an internal filename.
If userprog is not found, the compilation fails.
The user program can use CBL_EXIT_PROC to perform some post-build processing.