Model without Database?

[eluser]Unknown[/eluser]
I've just started playing with CI and from what I've seen thus far, I'm very enthusiastic about transitioning some of my own home-brew MVC code over to something more manageable.

However, I do have a question... I basically have an app that needs to query against a good bit of data which resides in flat files. I already have some code to do all of this and get the data of them, however I'm not sure of the appropriate place to put this logic?

I would consider this code to be my app's model, but it appears that I get added database code by sub-classing Model (as a bit of an aside, are there API docs describing these built-in superclasses, or should I just look at the source?). So, I'm not sure that sub-classing Model is appropriate here. From looking at the guide, a CI Helper also seems appropriate.

Your feedback/thoughts are appreciated.

Thanks,

--Dan