What are you actually trying to achieve here? You've described how you're trying to achieve it but not what you're actually trying to achieve. If you want a RichTextBox and a ListBox to occupy the same area then why don't you just add them to the same form with the same Size and Location? You can show and hide or change the z-order as required so the user can only see one at a time. You could also create a user control containing both and then treat them as a single unit.