[NumLock]

у меня все получилось:

Код:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TMyForm = class(TForm)
  public
    function GetLabel: TLabel; virtual; abstract;
  end;

  TForm1 = class(TMyForm)
    Label1: TLabel;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    function GetLabel: TLabel; override; 
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TheLost(MyForm: TMyForm);
begin
  MyForm.GetLabel.Caption:='TheLost';
end;

function TForm1.GetLabel: TLabel;
begin
  Result:=Label1;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  TheLost(Self);
end;

end.