Jose, Are you having discussions about this with the developer outside of their mailing lists? From what I found on the different lists at http://www.ossec.net/main/support/ there haven't been any updates since '09. It seems to me that for them to add exception/s is a trivial change. Why is this taking so long? What can we do to speed this up a bit? I took the liberty of making the 'suggestion' on their request page ( http://ossec.uservoice.com/forums/18254-general/suggestions/1543503-debian-package), if people would like to vote it up.
Cheers, Ciarán