[syslog-ng] Injecting environment variables?

New to the list, but looking for some pointers: It is possible to get shell variables interpreted and defined in the context of the syslog-ng.conf file? I'm trying to get the value from a shell/environment variable to be added to a logged message. I've tried various forms of templates in the destination without much success. template("<$PRI> $DATE $HOST $MSG $someENVvar \n") template_escape(no)); Static text works find, but the var ends up being blank... For reasons I won't belabor, I can't use tags as added by the source. Apologies if this has been covered previous - I didn't see anything from scanning the archives. Thanks. Jim.