[syslog-ng] Regular expressions in rewrite

Is there a way to use regular expressions when setting a value in a rewrite rule? Something like: rewrite r_rewrite_set_host{ subst("^[a-z]+\-([a-z]+).*$", "$1", value("HOST")); set("HOST" value("location") condition( filter(f_filter_hostnames) ) ); }; But without changing the actual log message. The goal is to create a variable from a regular expression of the host field in the message that I can then use in a destination path. Thanks, -Mark Mark Faine System Administrator SAIC/NICS 215 Wynn Dr. 5065 Huntsville, AL 35805 256-961-1295 (Desk) 256-617-4861 (Work Cell)