JCL-variable-substitution exit

EQQJVXIT contains an assembler sample of the JCL-variable-substitution exit. When you define a JCL variable, you can specify the name of an exit that is called when substitution of the variable is required. The exit can be called at either job setup or job submission, but is not called for promptable setup-variables. For System Automation command variables, the exit is invoked at command submission. You can use the exit to supply the value of a variable.