I have main window (called MainWindow) which holds Grid consisting of 4 cells. I have a button in first cell (called cmdAddWindow). I have also another window (called AddWindow).

I want that AddWindow window to be in fourth cell (Grid.Row="1", Grid.Column="1" called cellAddWindow) of MainWindow window when I press cmdAddWindow button. As window can be only a top element and can't be nested into other elements, then I can't just add it to children collection of that cellAddWindow cell. How to achieve it?