monitoring logs only if they exist

[Jon Hittner <jhittner (at) vmsinfo.com>]

I have machines that may or may not have a specific log file.   How do I 
configure hobbit to only retrieve the logs if they exist?   Right now, I have 
msgs yellow with "Logfile not accessible" on any host without this log and I 
would like to have them show up as green.

Thanks
Jon