[syslog-ng] Filter out host from netmask range

I am trying to remove a specific set of hosts from a network range using filters. for example, I have the following: filter f_home_subnet { ( netmask("192.168.0.0/24") ); }; I now want to exclude some specific hosts, let's say 192.168.0.10 and 192.168.0.20. My attempts of adding "not host" to the above doesn't seem to work. Any pointers / suggestions would be greatly appreciated. Thanks, Ian