public delegate void SelectionChangedEventHandler(object sender, EventArgs e);
public event SelectionChangedEventHandler Selection_Changed;

private void comboBox_SelectionChanged(object sender, Telerik.Windows.Controls.SelectionChangedEventArgs e)
{
       RaiseSelection_Changed(e);
}

public Object RaiseSelection_Changed(RoutedEventArgs e)
        {
           ///some code
        }