Modify the LoadL_config.local on the machine(s) that you want to accept this class of jobs. In this example, you would modify machine B's LoadL_config.local file. To do this, add a class statement similar to:
CLASS = {"NQS" "a" "b" ....}
where NQS is the name of the class of jobs that will be routed to the machines that run NQS, and a and b are names of additional classes.