Here's the ActiveX control which if you put it on the VB form will find out the supported (and of course registered) interfaces of all the sibling controls on the Form. It shows all the interfaces as a tooltip when you hover over any control on the form by hooking the "ToolTipText" extended property of the control. The steps are :
1.Enumerate all the controls on the Form using IOleContainer::EnumObjects()
2.QI each control for all the registered interfaces
3.Create a ToolTip string and assign it to the "ToolTipText" extended property of the control via IOleControlSite::GetExtendedControl()
VB does not allow the tooltips on the new line for its extended property. So I need to somehow send TTM_SETMAXTIPWIDTH to its TT control.
It will work for VB only. I have tested it on VB6.