I'm not sure that I understand what you really want to do. But yes, you can change the Endevor return code to 8 by setting the MAXRC=4 in the generate processor. Then the element will FAIL if the jobscan gets a return code 8. If this happens they will not be able to Move the element. If you don't want to FAIL the element and prevent the Move, then you need to keep the MAXRC=8. However, you could also code the jobscan in the Move processor if that fits your requirement better.
Maybe if you explain what you are trying to accomplish we can give you some other ideas.
Kevin