Is it possible to have this winform design pattern in C#?

I'm creating an application and I'm thinking of the global pattern that it should have.

The application should have a global menu and some MDI childs (in a Tab Manager). Each MDI Child should behave separately. Means that an MDI child should be able to show modal window and not block the other ones.

But I can't find an idea for this. When I display a modal form from an MDI child, all the application is blocked.

Does anyone have a trick on how to make this please ?

Thank you.