You'd have to write a shell namespace extension. See Michael Dunn's article "The Complete Idiot's Guide to Writing Namespace Extensions"[^]. Stability. What an interesting concept. -- Chris Maunder

The subclassing of a window can occur per window instance or for the entire class, meaning for the entire process. So, if you want to subclass all windows for a single dialog, you need to subclass each instance of a child control window separately. You replace the window procedure for the window's instance. -> SetWindowLong(hWnd, GWL_WNDPROC, ... ); If you want all child windows to be modified for the entire application, then you can subclass the window procedure globally by replacing the window class's window procedure with your own code. -> SetClassLongPtr(hWnd, GCLP_WNDPROC, ... );

Hi, Is this answer still valid while using Visual Studio 2019 ? The id IDD_FILEOPEN_EX does not exists. Do I need to include another RC file if I include dlgs.h ? Thanks. I'd rather be phishing!