ActionScript 3.0 :: Create A Reference To Variable/function Using Strings?

I'm wondering how I can create a reference to a function/variable by using strings. Sorry if I'm not explaining the problem well, but let me show you what I mean in an example:You can create a reference to a class using strings by using the getDefinitionByName as follows:var classRef:Class = getDefinitionByName("myClass") as Class;var myClass1:classRef = new classRef();Similarly, how do you refer to functions and variables? The reason why I want to know is because I'm trying to implement a function which takes in the event handler name as the parameter, and what the function essentially does is that it adds an event listener with the associated handler (based on the parameter) to an object, something like this:

public function addListener(handler:String):void {
mc.addEventListener(Event.ENTER_FRAME, "on" + handler);
}

[code].....