[Updated] Attached Properties to UserControl

[Mc_Topaz]

I have a UserControl which a bunch of Controls. In the UserControl there is TextBlock displaying a text as a title. The title is implemented as a DepedencyProperty in my UserControl and I can easily set the TextBlock's value in the MainWindow's XAML code. Like this:

Notice my custom Title property. I also have a button (Button1) in the UserControl with some properties. I want to specify the button's properties in the MainWindow XAML-code. But I don't manage to gain access to the buttons properties in the XAML-code if I use a similar Dependency property. I want this:

As you see I'm interesting to group the Button1's properties and be able to set its properties in the MainWindow's XAML-code. But with no success :sigh: Here is the code for the MyUserControl of what I have tried:

public class MyButton: FramworkElement
{
public ICommand Command { get; set; }
public string Header { get; set; }
}

public class MyUserControl : UserControl
{
public static readonly DependencyProperty Button1Property = DependencyProperty.RegisterAttached
(
"Button1",
typeof(MyButton),
typeof(MyUserControl),
new FrameworkPropertyMetadata(false, new PropertyChangedCallback(Button1Changed))
);

public MyButton Button1
{
    get { return (MyButton)GetValue(Button1Property); }
    set { SetValue(Button1Property, value);  }
}

public static void Button1Changed(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
    // ToDo
}

}

I found this weird because this kinda works when enclosing a control in a DockPanel. DockPanel.Dock="Left"