Thanks for reply.
Maybe I'm not understanding. We already run several different scripts for monitoring other things but I would like to use the simple file content monitoring supported out of the box.
I already do this for several other apps that have a fixed name logfile (or their startup scripts create a soft-link to the logfile that I use) but for a few apps we are deploying now the logfile has a timestamp embedded in it which obviously can't be represented by a static entry on the "with path" line -- so I would like to have monit execute a script every time it runs this check to determine the logfile path.