Hello,
I can't (quickly) think of a way to have one event generate another event, or cause events to only be created under certain conditions.
Assuming you are using these events to start a workflow, then what I would do is let all of the events be created and add a start condition to the workflow so it only starts for some events. In 4.7 you can add a start condition using transaction SWB_COND (be patient, it's very clunky and slow).
regards
Rick Bakker / hanabi technology