function GetStatusText(wndWindow: THandle;
  StatusBarClassName: string;
  PanelIndex: Byte): string;
var
  WndStatusBar: THandle;
  StatusBarText: array[0..$FFF] of Char;
begin
  Result := '';
  WndStatusBar := FindWindowEx(wndWindow, 0, PChar(StatusBarClassName), nil);
  if WndStatusBar <> 0 then
  begin
    if PanelIndex = 0 then
      SendMessage(WndStatusBar, WM_GETTEXT, $FFF, Longint(@StatusBarText))
    else
      SendMessage(WndStatusBar, SB_GETTEXT, PanelIndex, Longint(@StatusBarText));
    Result := StrPas(StatusBarText);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  // Read statustext from Internet Explorer
  label1.Caption := GetStatusText(FindWindow('IEFrame', nil), 'msctls_statusbar32', 0);
end;