Выкладываю сырцы этого регера. Код вроде бы итак понятен, если что не ясно - велкам в комменты.

Файл проекта.

program Project1;
uses
  Forms,
  Unit1 in 'Unit1.pas' {Form1};

{$R *.res}

begin
  Application.Initialize;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

Основной юнит.

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, StdCtrls, IdBaseComponent, IdComponent,
  IdTCPConnection, IdTCPClient, IdHTTP, IdCookieManager, IdAntiFreezeBase,
  IdAntiFreeze, IdCookie;

type
  TForm1 = class(TForm)
    IdHTTP1: TIdHTTP;
    Button1: TButton;
    IdAntiFreeze1: TIdAntiFreeze;
    IdCookieManager1: TIdCookieManager;
    Memo1: TMemo;
    Image1: TImage;
    Edit1: TEdit;
    Button2: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}
uses pngImage, IdMultipartFormData;

procedure TForm1.Button1Click(Sender: TObject);
var
  tmp: string;
  tmpImage: TMemoryStream;
  PNG: TPNGObject;
  Bitmap: TBitmap;
begin
  Bitmap := TBitmap.Create;
  IdHTTP1.AllowCookies := True;
  tmp := IdHTTP1.Get('http://by.ru/create.cgi');
  delete(tmp, 1, Pos('<label for="pin" >Ïðîâåðî÷íîå ñëîâî:', tmp) + 164);
  delete(tmp, Pos('">', tmp), Length(tmp));
  tmpImage := TMemoryStream.Create;
  IdHTTP1.Get('http://by.ru/' + tmp, tmpImage);
  tmpImage.Position := 0;
  PNG := TPNGObject.Create;
  PNG.LoadFromStream(tmpImage);
  bitmap.Assign(png);
  Image1.Picture.Graphic := Bitmap;
  tmpImage.Free;
  PNG.Destroy;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  Data: TIdMultiPartFormDataStream;
  CheckKey: string;
  tmpDomen, tmpPass: string;
  i: integer;
begin
  Data := TIdMultiPartFormDataStream.Create;
  Data.AddFormField('username', 'onlytest');
  Data.AddFormField('pin', edit1.text);
  CheckKey := IdHTTP1.Post('http://by.ru/create.cgi', Data);
  tmpDomen := chr(ord('a') + Random(28));
  Randomize();
  for i := 0 to 8 do tmpDomen := tmpDomen + IntToStr(Random(9));
  tmpPass := '';
  for i := 0 to 10 do tmpPass := tmpPass + IntToStr(Random(9));
  Data.AddFormField('domain', tmpDomen);
  CheckKey := IdHTTP1.Post('http://by.ru/create.cgi?step=1', Data);
  Data.AddFormField('password', tmpPass);
  Data.AddFormField('confirm', tmpPass);
  CheckKey := IdHTTP1.Post('http://by.ru/create.cgi?step=2', Data);
  Data.AddFormField('method-email-active', 'on');
  Data.AddFormField('email', 'mamiev@gmail.com');
  CheckKey := IdHTTP1.Post('http://by.ru/create.cgi?step=3', Data);
  CheckKey := IdHTTP1.Post('http://by.ru/create.cgi?step=4', Data);
  Data.Free;
  Memo1.Lines.Add('ftp://' + tmpDomen + ':' + tmpPass + '@ftp.by.ru-' + tmpDomen + '.by.ru');
// ftp://login:pass@ftp.by.ru-login.by.ru
end;

end.