Tracking Usage

Greetings!

I would like to know on how to track a users total tx/rx bytes for certains period. I am viewing this in simple queues and it is quite good, but moment the router reset it lose all setting. Maybe there is script to store this every week or whenever power is lost (this happen a lot in my country)

Many thanks!

No one has any ideas!?

This may help

http://wiki.mikrotik.com/wiki/Automated_Usage_Script_without_usermanager