[flexcoders] Custom renderers - need help

[markgoldin_2000]

I am still having problem understanding how to do some things with 
custom renderers.
Here is a scanario (The code is simplified):
There is a HBox. That would have a few children:
public class columnHeaderCheckBox extends HBox
{
  public function columnHeaderCheckBox()
  {
        super();
  }
  override protected function createChildren():void
  {
        super.createChildren();
        var leftSpace:Spacer = new Spacer();
        leftSpace.width = 2;
        addChild(leftSpace);
        checkBox = new CheckBoxHeaderRenderer();
        addChild(checkBox);
        var title:Label = new Label();
        title.text = "Set";
        addChild(title);
  }
}
CheckBoxHeaderRenderer is an extension of a checkbox.
I am setting a custom renderer for a header like this:
setOrderHeaderRenderer = new ClassFactory(columnHeaderCheckBox);
Gridreceiving.columns[4].headerRenderer = setOrderHeaderRenderer;
So far so good.
But what if I want to run some code on one of the children of 
columnHeaderCheckBox before it actually is shown? To make it more 
generic? So it might check for its parent and adjusts itself 
accordinally. Thus my question is, how can I execute a method of the 
child "checkBox" while a renderer is getting set to the header?

I am kind of stuck with that.

Thanks for any help.