Using An Object Method As EventListener In IE?

I'm working on a drag and drop HTML editor, in which blocks can be positioned. I need to build a controller which listens to mouse events and takes appropriate action (a state machine). The system is built using prototypes and objects. The Controller class looks like this (I removed some methods for simplification):

Code JavaScript:
/**
* Creates a controller for a document
*/
function Controller() {[code]....

The method 'handleMove' is entitled to handle a mouse move on the overlay. Because the 'this' keyword would not point to the Controller object I've written a wrapper according to the W3C EventListener interface (http://www.w3.org/TR/DOM-Level-2-Eve...-EventListener). This wrapper holds a reference to the object in which the method resides that's handling the event, so that the important 'document' attribute can be reached. This document holds the document that is being edited (it's of a custom type, and not to be confused with the document as in document.body)

The problem I now have is as follows. IE doesn't seem to be able to work with event handlers following the EventListener interface, but just functions. I need to get the object's reference there as well though, but this can't be done using an anonymous function, as at the moment it will be run it will be in a different scope, and not be able to reach the controller any more.Just using a global holding that reference variable, a method I used before, is not sufficient, as there may be multiple instances of the editor running on the same page.I have no problems in FFox, Opera, and Safari. Just IE because it uses an alternative event listener model.