/// <summary>
/// Возвращает все внутренние контролы.
/// </summary>
/// <param name="parentControl">Корневой Контрол.</param>
/// <returns></returns>
public static IEnumerable<Control> GetInnerControls(this Control parentControl)
{
            Contract.Requires(parentControl != null);

            return parentControl.Controls.Cast<Control>()
                .SelectMany(c => new Control[] { c }.Union(c.GetInnerControls()));
}

........

var button1 = MyForm.GetInnerControls().OfType<Button>().FirstOrDefault(b=>b.Name=="Button1");