[BlackCash]

Ну попробуй такой вариант:
/////////////////////////////////////////////////////////
unit Unit1;

interface

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

type
TForm1 = class(TForm)
Panel1: TPanel;
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

type
TPanelMoveThreard = class(TThread)
private
Procedure MovePanel;
public
Procedure Execute;override;
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

Procedure TPanelMoveThreard.MovePanel;
begin
Form1.Panel1.Left := Form1.Panel1.Left + 1;
Sleep(100);
end;

Procedure TPanelMoveThreard.Execute ;
var
i: integer;
begin
for i := 0 to 400 do
MovePanel;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
MovePanel: TPanelMoveThreard;
begin
MovePanel := TPanelMoveThreard.Create(False);
MovePanel.FreeOnTerminate := True;
MovePanel.Resume;
end;

end.