Hello Torek,
Without having access to more documenation it sounds like you have a running environment problem.
If your REQ rule includes the Address ISPEXEC statement you should then be running it under a valid ISPF environment.
In our sample provided in CCLXRULS dataset the REQ rule OPAODIGL should give you examples how to code your rule.
Since REQ rules can use Address ISPEXEC services then just make sure that macro ENDMAC has been made accessible to the SYSPROC DD concatenation of your OPSMAIN task.
I hope this all helps you today.
If it does not then please cut a new Customer Support ticket so we can help you further.
Regards, Cesar