[NumLock]

собрал все воедино:

Код:

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    OpenDialog1: TOpenDialog;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    procedure OpenDialog1IncludeItem(const OFN: TOFNotifyEx; var AInclude: Boolean);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{ TForm1 }

procedure TForm1.OpenDialog1IncludeItem(const OFN: TOFNotifyEx;
  var AInclude: Boolean);
var
  PathName: array[0..MAX_PATH-1] of Char;
  Ext: String;
  IDL: PItemIDList;
begin
  SHGetPathFromIDList(PItemIDList(OFN.pidl), @PathName);
  Ext:=ExtractFileExt(PathName);
  AInclude:=Ext='';
  IDL:=ofn.pidl;
  if not AInclude then IDL^.mkid.abID[0]:=0;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  OpenDialog1.Options:=OpenDialog1.Options+[ofEnableIncludeNotify];
  OpenDialog1.Options:=OpenDialog1.Options-[ofOldStyleDialog];
  OpenDialog1.Filter:='*.*|?*';
  OpenDialog1.OnIncludeItem:=OpenDialog1IncludeItem;
  if OpenDialog1.Execute then ShowMessage(OpenDialog1.FileName);
  PostMessage(Handle, WM_CLOSE, 0, 0);
end;

end.