How to substitute application/context menu with custom one? (for an external application)

See more:

C#

Windows

menu

context-menu

, +

What I want to do:

I'm sending to an external application a mouse down signal (for left or right button). And when in the result of this action application shows some kind of menu (application menu or context menu) I need to:

- detect the fact that menu was created;
- get screenshot|image of this menu (or get its items list);
- hide the menu (or if it's possible not to show it in a first place and just get screenshot/items list);
- *here I will show to user a representation of the menu inside of my application and user will choose some action*;
- send the results of users action back to the application.

How can I do something like this?

I've tried to get context menu HWND handle by calling FindWindowEx() with desktop as a parent handle and class "#32768". Like described here https://stackoverflow.com/questions/12411782/accessing-a-right-click-context-menu-from-an-external-application. But I'm always getting null as a result.

But it's only a partial solution of one of the stated problems anyway so I would be grateful if you have ideas about alternative approaches.