I found a case from 2014 where this was supposed to be fixed.
But can not find anything in the release notes or docs on this.
I am doing some further reseach on this.
even though you can not do a $ to show variables is it failing when testing?
the .cfg would look something like
runcommandonmatch = yes commandexecutable = ./probes/system/logmon.sh commandarguments = ${var}