Module system

[eluser]daveario[/eluser]
For my latest work I need an extensible module system for CI. A module has to handle database connections and views.

The only problem is:
A module controller extends a model. If I want to address a function that displays a page, I am doing it with another controller who analyses the url, for example:

Code:

modulename/page

The controller knows which module is meant and which function it should call.

But I can't call the function because the module name is a variable.

Code:

$this->MODULENAME->FUNCTION();

$this->$module->$function(); # doesn't work.

Do you know how to solve that?
Thanks in advance!