Auditing only when auid and uid differ

I want to track what people are doing when then change their userid. Basically I would like to write : -a exit,never -F arch=b32 -S all -F auid=4294967295 -a exit,never -F arch=b64 -S all -F auid=4294967295 -a exit,always -F arch=b32 -S all -F auid>1000 -F uid!=auid -k userchange -a exit,always -F arch=b64 -S all -F auid>1000 -F uid!=auid -k userchange However it seems that it's not a valid syntax. Is there a way to achieve that. Philippe ________________________________ Ce message et les pi?ces jointes sont confidentiels et r?serv?s ? l'usage exclusif de ses destinataires. Il peut ?galement ?tre prot?g? par le secret professionnel. Si vous recevez ce message par erreur, merci d'en avertir imm?diatement l'exp?diteur et de le d?truire. L'int?grit? du message ne pouvant ?tre assur?e sur Internet, la responsabilit? de Worldline ne pourra ?tre recherch?e quant au contenu de ce message. Bien que les meilleurs efforts soient faits pour maintenir cette transmission exempte de tout virus, l'exp?diteur ne donne aucune garantie ? cet ?gard et sa responsabilit? ne saurait ?tre recherch?e pour tout dommage r?sultant d'un virus transmis. This e-mail and the documents attached are confidential and intended solely for the addressee; it may also be privileged. If you receive this e-mail in error, please notify the sender immediately and destroy it. As its integrity cannot be secured on the Internet, the Worldline liability cannot be triggered for the message content. Although the sender endeavours to maintain a computer virus-free network, the sender does not warrant that this transmission is virus-free and will not be liable for any damages resulting from any virus transmitted.