Regex for variable monitor recv string

Try:

totalReg=\"^([1-9]|[1-9][0-9]|[1-9][0-9][0-9]|[1-9][0-9][0-9][0-9])$\"

Someone else might have a niftier way of doing it but this should work. Note it could be a pretty resource-intensive test. You will probably want to benchmark it to see what adjustments you want to make to the monitor's interval and timeout values.