oh yes what a plum!

 big thanks for your help

Looks good to me. I would just add a break or return statement after you remove the child element from the collection because there should only be one element of this type in the collection. Once you find and remove it, theres no point to looping over the other elements.

Big THANKS! I have managed to do it... i have written this, is it correct? or is there a better more efficent way of doing it?

 public void AfterCreateChildElements(Infragistics.Win.UIElement parent)
        {
            if (!(parent is RibbonCaptionAreaUIElement))
            { return; }

            foreach (UIElement child in parent.ChildElements)
            {
                if ((child is QatQuickCustomizeToolUIElement))
                {
                    parent.ChildElements.Remove(child); 
                }
              
            }
        }

        public bool BeforeCreateChildElements(Infragistics.Win.UIElement parent)
        {
            // return false so PositionChildElements will get called
            // to do the default child element creation
            return false;
        }