Step : 1 - Create new command as a DepenedecyProperty and implement it 

Steo : 2 -  Bind Command property in the button the the MyButtonCommandProperty in your UserControl.


public Class YourUserControl: UserControl 
 {

      public YourUserControl()
      {
          MyButtonCommad = new RelayCommand
                     (
                         () => { // do some stuff in execute delegate},
                         () => { return true ;}                                                        
                     );
      }

      public bool MyButtonCommad 
      {
           get { return (ICommand)GetValue(MyButtonCommandProperty ); }
           set { SetValue(MyButtonCommandProperty , value); }
      }    

      public static readonly DependencyProperty MyButtonCommandProperty = 
                             DependencyProperty.Register("MyButtonCommad ", typeof(ICommand),new FrameworkPropertyMetadata(null));

 }


// XAML : 

<Window>
      <StackPanel>
          <Button Command={Binding ElementName=control1,Path=MyButtonCommad ,Mode=OneWay/>
          <YourUserControl: x:Name="control1" />
      </StackPanel>
 </Window>