with ImageEnView1.IO do
  LoadFromFileAuto(ExecuteOpenDialog());

procedure TfrmMain.dlgOpenImageCreateCustomControls(Sender: TObject);
const
  BUTTON_TOP    = 0;
  BUTTON_LEFT   = 410;
  BUTTON_WIDTH  = 140;
  BUTTON_HEIGHT = 25;
var
  p: TWinControl;
  btn: TButton;
begin
  p := (sender as TOpenImageEnDialog).InfoPanel;
  btn := TButton.Create(p);
  btn.Parent := p;
  btn.Caption := 'Paste from Clipboard';
  // Note: Need to handle screen scaling
  btn.SetBounds( BUTTON_LEFT, BUTTON_TOP, BUTTON_WIDTH, BUTTON_HEIGHT );
  btn.OnClick := OpenDialogPasteBtnClick;
end;

procedure TfrmMain.OpenDialogPasteBtnClick(Sender: TObject);
var
  dialogHandle: HWND;
begin
  dialogHandle := GetActiveWindow;

  if ImageEnView1.Proc.CanPasteFromClipboard() = False then
  begin
    MessageDlg( 'There is no image on the clipboard', mtInformation, [ mbOK ], 0 );
    SetForegroundWindow( dialogHandle );      // Bring to front
  end
  else
  begin
    // Close the Open Dialog
    if dialogHandle <> 0 then
      EndDialog( dialogHandle, IDCANCEL );

    ImageEnView1.Proc.PasteFromClipboard()
  end;
end;