Flex 4.5: How to set 'textAlign' DefaultGridItemRenderer via AS3?

I can't figure this out: how to set 'textAlign' property for default itemRenderer in AS3 (not mxml)??

I need to adjust it based on type's properties, 'int' or 'Number' aligned right, 'String' aligned left and so on.

I'm using spark DataGrid and listening FlexEvent.CREATION_COMPLETE event; I can't cast itemRenderer to DefaultGridItemRenderer, and ClassFactory doesn't provide setStyle method.

public function adjustGrid (e:Event):void {

     for (var i:int=0; i<grd.columns.length; i++)

     {

                    //this causes an cast error


          var gridColumn:GridColumn = GridColumn(grd.columns.getItemAt(i)); DefaultGridItemRenderer(gridColumn.itemRenderer).setStyle("textAlign", "right");

          //ClassFactory(gridColumn.itemRenderer).setStyle("textAlign", "right");

     }

}

Any help I will appreciate. Thanks.