How do I use a menu handler with a containercontrol?

I have a main Window (wMain) and embed a container control in it which has a listbox. I’d like to use a menu item to open a record in the listbox. I’m guessing I can do this, since containercontrol is allowing me to add a menu handler, but I’m stumped after that very simple first step. The cc is not autofilling in the menuitem as is normal in a window (and I don’t expect it to). But while adding “FileOpen” and putting code in it does not seem to throw any errors, neither does the menuitem show as enabled.

I have added the menuitem i want to “MainMenuBar” - FileOpen and that menu bar is chosen in the wMain window.

Where and how can I enable that menuitem?

in the EnableMenuItem event of the containercontrol.