[FlyInDream]

Код:

function AppendList (var AList: TStringList): TStringList;
begin
  AList.Add('Это новая строка!');
  Result:= AList;
end;

Код:

procedure TForm4.btn1Click(Sender: TObject);
var
myList: TStringList;
begin
  myList:= TStringList.Create();
//  AppendList (myList);
  mmo1.Text:= AppendList (myList).Text;
  myList.Free;
end;