Following from the tool shown in Util - Windows Handles - View Handle Screenshot v1.0, the next step was to create a tool that shows (for the selected Win32 Window) the handle's children structure (i.e. what 'child windows' exists for the selected window/control)
You can download the 1 Mb tool from Util - Windows Handles Viewer (with Child Windows) v1.0.exe
Here is what the tool looks like (with the 'target icon' used to select the control):
Here is the Pdf with the 'how the script was created' step-by-step guide: