function GetText(WindowHandle: hwnd):string;
var
  txtLength : integer;
  buffer: string;
begin
  TxtLength := SendMessage(WindowHandle, WM_GETTEXTLENGTH, 0, 0);
  txtlength := txtlength + 1;
  setlength (buffer, txtlength);
  sendmessage (WindowHandle,wm_gettext, txtlength, longint(@buffer[1]));
  result := buffer;
end;

function GetURL:string;
var
  ie,toolbar,combo,
  comboboxex,edit,
  worker,toolbarwindow:hwnd;
begin
  ie := FindWindow(pchar('IEFrame'),nil);
  worker := FindWindowEx(ie,0,'WorkerA',nil);
  toolbar := FindWindowEx(worker,0,'rebarwindow32',nil);
  comboboxex := FindWindowEx(toolbar, 0, 'comboboxex32', nil);
  combo := FindWindowEx(comboboxex,0,'ComboBox',nil);
  edit := FindWindowEx(combo,0,'Edit',nil);
  toolbarwindow := FindWindowEx(comboboxex, 0, 'toolbarwindow32', nil);
  result := GetText(edit);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Edit1.Text := GetURL;
end;