Extending dbutil

[eluser]Militis[/eluser]
I use the csv_from_result function of dbutil so a user can download a copy of our orders table. What I'd like to do is format and/or rename the headings.

Normally, I'd just extend the class and go from there. Problem is, dbutil isn't in the libraries, helpers, or plugins system folders. Do I just need to add a "database" folder to my application folder to be able to extend the dbutil class?

If this has already been answered somewhere else, please link me to it. I did a search but didn't find anything relevant.