출처

http://www.devpia.com/MAEUL/Contents/Detail.aspx?BoardID=18&MAEULNO=8&no=2027&page=2 

 public static class FindByNameUtil
 {
  public static T FindByName<T>(this object targetClass, string name) where T : class
  {
   System.Reflection.FieldInfo fi = targetClass.GetType().GetField(name, System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
   return fi.GetValue(targetClass) as T;
  }

  public static T FindByName<T>(this string name, object targetClass) where T : class
  {
   System.Reflection.FieldInfo fi = targetClass.GetType().GetField(name, System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic);
   return fi.GetValue(targetClass) as T;
  }
  public static System.Windows.Forms.Label Is_Label_From(this string name, object targetClass)
  {
   return FindByName<System.Windows.Forms.Label>(targetClass, name);
  }
  public static System.Windows.Forms.TextBox Is_TextBox_From(this string name, object targetClass) 
  {
   return FindByName<System.Windows.Forms.TextBox>(targetClass, name);   
  }
  public static System.Windows.Forms.TextBox TextBox(string name, object targetClass)
  {
   return FindByName<System.Windows.Forms.TextBox>(targetClass, name);
  }
  public static System.Windows.Forms.Label Label(string name, object targetClass)
  {
   return FindByName<System.Windows.Forms.Label>(targetClass, name);
  } 
 }

사용방법

 private void Form1_Load(object sender, EventArgs e)
        {
            for (int i = 1; i <= 5; i++)
            {
                //use 1
                string myControl = "label" + i.ToString();
                myControl.FindByName<Label>(this).Text = "1111";
               

                //use 2
                Label tmp = myControl.FindByName(this);
                tmp.Text = "1111";

                //use 3
                this.FindByName<Label>("label" + i).Text = "1111";

                //use 4
                ("label" + i).FindByName<Label>(this).Text = "1111";

               //use 5
               ("label" +i).Is_Label_From(this).Text = "1111";

              //use 6

             FindByNameUtil.Label("label" + i, this).Text = "123";

            }           
        }