[syslog-ng] composing file names with system varible

Hi, i've on my machine file with some name, for example: # cat /var/hostname smeagol now i want to have log files like this: /var/log/smeagol-all.log if i change content of /var/hostname and then restart syslog-ng, syslog-ng shoud start logging to files with new name. is it possible? mabye no directly but with some workaround? regards, p.