I seem to recall some discussion about this, but I don't know if there was a solution.
A quick & dirty method would be to create a set of filter rules in the spam and ham accounts that keep the mail from specific users in the Inbox, and delete everything else. However, I'm not sure how well you can do this with ZCS 5.0.11. In more modern ZCS, spam reports are delivered with the reporting user's email address in the subject. E.g.