Assuming that your resource is setup to capture Application event logs under metric named ApplicationEventLogs, here is a way where you can setup an alert that is raised when CloudMonix finds an entry in event logs with the word "Exception" in its description

Alert expression: 


Any(ApplicationEventLogs, "Contains(Message,\"Exception\")")


Kindly notice escaped quotes.  Learn more here, for further assistance with setting up expressions with aggregation formulas.