[syslog-ng] Strip off messagges

Hi Guys, Most likely I'm just to ask a stupid question, but never mind.. Is it possible someway to strip off part of the message that syslog-ng sends or receive? It could be very useful to remove some non RFC compliant timestamps from messages written by application that doesn't use syslog-ng (eg.: squid, openwebmail ecc.). Thanks for patience Raffaele