This is an advanced version of the editor posted in the Showcase sub forum. It comes with a dedicated DLL that adds menus to the main menu bar and also appends additional menu items to the default resource menu. A number of functions have been removed from the editor and put into the DLL and the editor has had "Merge Text" capacity added to the file menu.
The DLL subclasses the main window and performs the DLL based menu processing in that subclass. As the DLL has access to the main window component handles, you can do just about anything with the DLL, dialogs, other apps contained in the DLL or even additional toolbar buttons for DLL algorithms.
Just be aware that while CodeEdit is robust and reliable, you can make a mess of it with direct access from the DLL.