In a PL/I program, invoke a program-coded dialog function named
PROG1, and pass it a parameter string consisting of ABCDEF. Set the
program variable BUFFER to contain:
SELECT PGM(PROG1) PARM(ABCDEF)
Set
program variable BUFLEN to the length of the variable BUFFER. Issue
the command:
CALL ISPEXEC (BUFLEN, BUFFER);