| email      | first name | last name | moderator | admin |
+------------+------------+-----------+-----------+-------+
|sm@mail.com | max        | biagi     |      1    |   1   |

//Create new user
                    $usermeta = array();
                    $usermeta['first_name'] = ucfirst ($first_name);
                    $usermeta['last_name'] = ucfirst ($last_name);
                    $usermeta['password'] = wp_hash_password( $email );
                    $user_login = strtok($email, '@');
                    $user_id = bp_core_signup_user( $user_login, $email, $email, $usermeta );

                    //Add user to group
                    groups_join_group($group_id, $user_id );

                    //Promote user to group moderator
                    if($mod){
                        groups_promote_member($user_id,$group_id,'mod');
                    }
                    //Promote user to group administrator
                    if($admin){
                        groups_promote_member($user_id,$group_id,'admin');
                    }
                }

$user_id = wp_insert_user(array(
                            'user_login' => $user_login,
                            'user_pass' => wp_hash_password( $email ),
                            'first_name' => $first_name,
                            'last_name' => $last_name,
                            'display_name' => $first_name . ' ' . $last_name,
                            'user_email' => $email,
                            'user_nicename' => $first_name