[Demonuka]

Думаю, примерно аналогично...

Код:

var
MyForm: TForm;
.....
begin
 for i := 0 to application.ComponentCount - 1 do
  if application.Components[i] is TForm then
    if (application.Components[i] as TForm).Caption='То что нужно' then begin
      MyForm:=application.Components[i] as TForm;
      for j := 0 to MyForm.ComponentCount - 1 do
         if MyForm.Components[j] is TMemo then
             (MyForm.Components[j] as TForm).Lines.Add('Текст какой то');