How separate login name ?

I would like to know if it's possible to separate login and name. For example, if my name is "George Dupont" and my login is "gdupont", the name user into Drupal is "George Dupont" and not "gdupont" (actually, in my account, my name is "gdupont").
In the function ldapauth_login_validate(), there is (line 255):

// Authenticate LDAP user.
  if (!($dn = _ldapauth_auth($name, $pass)))
    return;

  $account = user_load(array('name' => $name));

  if (!isset($account->uid)) {
    // Register this new user.
    if ($ldap_user = _ldapauth_user_lookup($name)) {
      // Generate a random drupal password. LDAP password will be used anyways.
      $pass = user_password(20);

      // If mail attribute is missing, set the name as mail.
      $init = $mail = key_exists(($_ldapauth_ldap->getOption('mail_attr') ? $_ldapauth_ldap->getOption('mail_attr') : LDAPAUTH_DEFAULT_MAIL_ATTR), $ldap_user) ? $ldap_user[$_ldapauth_ldap->getOption('mail_attr')][0] : $name;
      
      $userinfo = array('name' => $name, 'pass' => $pass, 'mail' => $mail, 'init' => $init, 'status' => 1, 'authname_ldapauth' => $name, 'ldap_authentified' => TRUE, 'ldap_dn' => $ldap_user['dn'], 'ldap_config' => $_ldapauth_ldap->getOption('sid'));
      $user = user_save('', $userinfo);
      watchdog('ldapauth', 'New external user %name created from the LDAP server %server.', array('%name' => $name, '%server' => $_ldapauth_ldap->getOption('name')), WATCHDOG_NOTICE, l(t('edit'), 'user/'. $user->uid .'/edit'));
    }
  }

So the name user is the login user.
Perhaps it would be better to offer to new user to choose a name instead of requiring that it is the login. No ?
Or maybe it's possible by other means ? but i don't know it.