Route using database information

[eluser]WanWizard[/eluser]
Hello from this Newbie.

I'm planning to rewrite our current web framework (which has been around since the PHP3 days, and in dire need of a makeover), and the plan is to use this fantastic framework as the foundation.

While writing down the new architecture and design (yes, I'm old ;-)), I have stumbled upon an issue that I don't quite know how to address.

Our current system uses a 'content-tree', which is basically the URI structure of the site, and is stored in a database. The system administrator can map any leaf of the tree (a specific URI) to a function, either static content, a core module (p.e. user administration) or a custom application (p.e. products).

This means in CI terms (if I understand it correctly) that I need to route based on database contents. From what I gather I can do that in:
- /config/routes.php, generate a custom $route['(.*)'] = for every URI requested
issue: no database functionality here, no URI functionality here
- /system/application/libraries/MY_Router.php, and rewrite the _validate_request() function
I do have URI functionality here, but still no database access
- /system/application/controller/dispatcher.php, and use a $route['(.*)'] = "dispatcher";
I have all CI functionality here, but basically I need to duplicate router and CI core code here to be able to load the correct controller that is the result of the content-tree lookup. Not best practice either.

Anyone any thoughts on how to approach this?