Sounds like you’re trying to do exactly the same sort of thing I wrote into my usage monitor script.
http://wiki.mikrotik.com/wiki/Automated_Usage_Script_without_usermanager
I saved a number of values into the queue name to persist through reboots. I’m saving mine every hour.
It would however be great if we could get a comment space for the queue rather than changing the queue name itself please normis? 
This would mean I could allow end users to view their own IP queue with a name rather than