[NumLock]

Код:

uses
  WinInet,
...
type
  TForm1 = class(TForm)
    Edit1: TEdit;
    procedure FormCreate(Sender: TObject);
...
procedure TForm1.FormCreate(Sender: TObject);
var
  lpUrlComponents: URL_COMPONENTS;
  buf: array [0..$ff] of Char;
  dwUrlLength: DWORD;
begin
  ZeroMemory(@lpUrlComponents, SizeOf(URL_COMPONENTS));
  lpUrlComponents.dwStructSize:=SizeOf(URL_COMPONENTS);
  lpUrlComponents.lpszScheme:='http';
  lpUrlComponents.lpszHostName:='msdn.microsoft.com';
  lpUrlComponents.nPort:=80;
  lpUrlComponents.lpszUrlPath:='en-us/library/windows/desktop/aa384473.aspx';
  lpUrlComponents.lpszExtraInfo:='?param1=true&param2=нет';
  dwUrlLength:=SizeOf(buf);
  if not InternetCreateUrl(lpUrlComponents,
    ICU_ESCAPE,
    @buf[0],
    dwUrlLength) then RaiseLastOSError
  else Edit1.Text:=Copy(buf, 1, dwUrlLength);
end;

см. в Edit1 на параметр param2=нет