How do I create an IIS application and application pool using InnoSetup script

• Create an IIS application.
• Create a new IIS application pool and set it's .NET version to 4.
• Set the application pool of the new application to the new application pool.

procedure CreateIISVirtualDir();
var
  IIS, WebSite, WebServer, WebRoot, VDir: Variant;
  ErrorCode: Integer;
begin
  { Create the main IIS COM Automation object }

  try
    IIS := CreateOleObject('IISNamespace');
  except
    RaiseException('Please install Microsoft IIS first.'#13#13'(Error ''' + GetExceptionMessage + ''' occurred)');
  end;

  { Connect to the IIS server }

  WebSite := IIS.GetObject('IIsWebService', IISServerName + '/w3svc');
  WebServer := WebSite.GetObject('IIsWebServer', IISServerNumber);
  WebRoot := WebServer.GetObject('IIsWebVirtualDir', 'Root');

  { (Re)create a virtual dir }

  try
    WebRoot.Delete('IIsWebVirtualDir', 'eipwebv4');
    WebRoot.SetInfo();
  except
  end;

  VDir := WebRoot.Create('IIsWebVirtualDir', 'eipwebv4');
  VDir.AccessRead := True;
  VDir.AccessScript := TRUE;
  VDir.AppFriendlyName := 'Easy-IP Web Client';
  VDir.Path := ExpandConstant('{app}');
  try
    VDir.AppPoolId := 'Classic .NET AppPool';
  except
  end;

  VDir.AppCreate(True);
  VDir.SetInfo();
end;

var
  global_AppCmdFilePath :String;
  global_IsIIS7 :Boolean;
  global_WebSites :SiteList;
  global_WebSiteName :String;
  global_vDir :String;
  global_AppCmdExitCode :Integer;

const
  IISServerName = 'localhost';
  IISApplicationPoolName = 'Test Pool';

  ERROR_NOT_FOUND = 1168;
  ERROR_NOT_SUPPORTED = 50;

  MD_APPPOOL_IDENTITY_TYPE_LOCALSYSTEM = 0;
  MD_APPPOOL_IDENTITY_TYPE_LOCALSERVICE = 1;
  MD_APPPOOL_IDENTITY_TYPE_NETWORKSERVICE = 2;
  MD_APPPOOL_IDENTITY_TYPE_SPECIFICUSER = 3;

  MD_LOGON_INTERACTIVE = 0;
  MD_LOGON_BATCH = 1;
  MD_LOGON_NETWORK = 2;
  MD_LOGON_NETWORK_CLEARTEXT = 3;

function ExecAppCmd(params :String) :Boolean;
var
  execSuccessfully :Boolean;
  resultCode :Integer;
begin
  execSuccessfully := Exec('cmd.exe', '/c ' + global_AppCmdFilePath + ' ' + params, '', SW_HIDE, ewWaitUntilTerminated, resultCode);

  global_AppCmdExitCode := resultCode;

  Result := execSuccessfully and (resultCode = 0);
end;

function CreateVirtualDirectoryForIIS6(physicalPath :String) :String;
var
  IIS, webService, webServer, webRoot, vDir, vDirApp :Variant;
  appPools, appPool :Variant;
  webSiteId :String;
begin
  webSiteId := GetWebSiteIdByName(global_WebSiteName);

  // Create the main IIS COM Automation object.
  IIS := CreateOleObject('IISNamespace');

  // Get application pools.
  appPools := IIS.GetObject('IIsApplicationPools', 'localhost/W3SVC/AppPools');

  try
    // Check if the application pool already exists.
    appPool := appPools.GetObject('IIsApplicationPool', IISApplicationPoolName);
  except
    // Crete the application pool.
    try
      appPool := appPools.Create('IIsApplicationPool', IISApplicationPoolName);

      appPool.LogonMethod := MD_LOGON_NETWORK_CLEARTEXT;
      appPool.AppPoolIdentityType := MD_APPPOOL_IDENTITY_TYPE_NETWORKSERVICE;

      appPool.SetInfo();
    except
      Result := 'Failed to create an apllication pool.';
      Exit;
    end;
  end;

  // Connect to the IIS server.
  webService := IIS.GetObject('IIsWebService', IISServerName + '/w3svc');

  // Get the website.
  webServer := webService.GetObject('IIsWebServer', webSiteId);
  webRoot := webServer.GetObject('IIsWebVirtualDir', 'Root');

  // Delete the virtual dir if it already exists.
  try
    webRoot.Delete('IIsWebVirtualDir', global_vDir);
    webRoot.SetInfo();
  except
    // An exception will be raised if there is not such a website.
  end;

  // Create the virtual directory.
  try
    vDir := WebRoot.Create('IIsWebVirtualDir', global_vDir);

    vDir.AccessRead := True;
    vDir.AccessScript := True;
    vDir.AppFriendlyName := 'Test friendly name';
    vDir.Path := physicalPath;

    vDir.AppCreate(False);

    vDir.SetInfo();
  except
    Result := 'Failed to create a virtual directory.';
    Exit;
  end;

  // Assign the application pool to the virtual directory.
  try
    vDir := webRoot.GetObject('IIsWebVirtualDir', global_vDir);

    vDir.AppPoolId := IISApplicationPoolName;

    vDir.SetInfo();
  except
    Result := 'Failed to assign the application pool to the virtual directory.';
    Exit;
  end;
end;

function CreateVirtualDirectoryForIIS7(physicalPath :String) :String;
var
  tempFileName :String;
  appPoolList :String;
  createAppPool :Boolean;
begin
  // Delete the application if it already exists.
  if not ExecAppCmd(Format('delete app "%s/%s"', [global_WebSiteName, global_vDir])) then
  begin
    if (global_AppCmdExitCode <> ERROR_NOT_FOUND) and (global_AppCmdExitCode <> ERROR_NOT_SUPPORTED) then
    begin
      Result := 'Failed to delete the application.  ' + GetErrorMessageByCode(global_AppCmdExitCode);
      Exit;
    end;
  end;

  // Check if the application pool already exists.
  tempFileName := ExpandConstant('{tmp}\AppPoolNames.txt');

  ExecAppCmd(Format('list apppool "%s" > "%s"', [IISApplicationPoolName, tempFileName]));

  if (LoadStringFromFile(tempFileName, appPoolList)) then
  begin
    createAppPool := (Pos(IISApplicationPoolName, appPoolList) = 0);
  end
  else
  begin
    createAppPool := True;
  end;

  // Create the application pool.
  if (createAppPool) then
  begin
    if not ExecAppCmd(Format('add apppool /name:"%s" /managedRuntimeVersion:v4.0', [IISApplicationPoolName])) then
    begin
      Result := 'Failed to add the application pool. ' + GetErrorMessageByCode(global_AppCmdExitCode);
      Exit;
    end;
  end;

  // Create the application.
  if not ExecAppCmd(Format('add app /site.name:"%s" /path:"/%s" /physicalPath:"%s" /applicationPool:"%s"', [global_WebSiteName, global_vDir, physicalPath, IISApplicationPoolName])) then
  begin
    Result := 'Failed to add the application. ' + GetErrorMessageByCode(global_AppCmdExitCode);
    Exit;
  end;

  Result := '';
end;