Sorry I didn't get back to you earlier but I have been away for a couple of days. The custom class works well. It will make my life a lot easier. Thanks!
Just a suggestion - Instead of having a box for 'Custom class', why not have a box called 'Class name'. it would normally hold the class name of that control (e.g wxListBox) but you could change it to something else if you want, e.g. wxCheckListBox. At the moment the custom control now has 'Class name' and 'Custom class'.
Les