[syslog-ng] Launching command with a certain value after extracting it from patterndb

Hi all, Is it possible to trigger a command after extracting a field using patterndb? For example I have the following log: Nov 4 15:18:10 myserver01 info ftps[876]: Rule Allow <ALLOW>: - MAP user:mytest IP:1.1.1.1 With patterndb, I can extract field user with for example, a value of $user. Can I trigger a command like "cat $user >> /tmp/users.log" without calling a script?? Thanks.