Как изменить порт, используемый принтером

uses Printers;

 {$IFNDEF WIN32}
  const MAX_PATH = 144;
 {$ENDIF}

 procedure TForm1.Button1Click(Sender: TObject);
 var
   pDevice : pChar;
   pDriver : pChar;
   pPort   : pChar;
   hDMode : THandle;
   PDMode : PDEVMODE;
 begin
   if PrintDialog1.Execute then begin
     GetMem(pDevice, cchDeviceName);
     GetMem(pDriver, MAX_PATH);
     GetMem(pPort, MAX_PATH);
     Printer.GetPrinter(pDevice, pDriver, pPort, hDMode);
     Printer.SetPrinter(pDevice, PDriver, 'FILE:', hDMode);
     FreeMem(pDevice, cchDeviceName);
     FreeMem(pDriver, MAX_PATH);
     FreeMem(pPort, MAX_PATH);
     Printer.BeginDoc;
     Printer.Canvas.TextOut(100, 100, 'Delphi Is RAD!');
     Printer.EndDoc;
   end;
 end;