TAdvToolBar Resizeable at Runtime?

Is there  way to make a TAdvToolBar (Office 2003 style) resizeable by the user at runtime?  I'm trying to have one of the toolbars be a resizeable edit box.

Sorry, there is currently no such option directly built-in. If you put the TAdvToolBar on a TAdvDockPanel and this TAdvDockPanel for example in a resizable panel, that could be a workaround by resizing the panel.

OK.  I think I can do what I want with a combination of TAdvToolBar.OnOptionClick and Application.OnMessage monitoring the wm_MouseMove message to simulate dragging the right handle to resize the toolbar.  The ScreenPoint reported by OnOptionClick seems to be about 5 pixels different than what is reported by the Application message though.  Any idea why that might be?.

Not sure what is causing this. Can it be screen coordinates versus client coordinates?
Do you compare the same coordinate type?