This is were Splunk or other Syslog tools does it work. I have added various view to show different types of error logs. See my signature.
But I agree that Splunk has a long way to clean up its logging system. Look at this post:
http://forum.mikrotik.com/t/logging-prefix-is-a-mess-sup-105353-sup-144261-waiting-for-mt-to-support-rfc-5424/111067/1
I have sent this to MT Support.