[syslog-ng] Quick filter question again

Hey all! Hope this is quick/easy. So I'm matching IP's that I don't want to see...filter below: message("66\.220\.") My issues is, this will match not only say 66.220.1.1, but also 166.220.1.1. I've tried changing to: message(" 66\.220\.") but that'd didn't fly. Any suggestions on how to more exactly match IP blocks? Thanks all. James