How to create a query to the database and display the value of a specific tag in html?

Question

PHP

PHP is weak, but I'm starting to understand something)
There is such a query to the database:

$buff = '';
        $db->query( "SELECT * FROM " . USERPREFIX . "_billing_history" . ( count($params) ? 'WHERE ' . implode(' and ', $params) : '') . "
                        ORDER BY {$sort} {$sort_by} LIMIT {$limit}" );
        while ( $row = $db->get_row() )
        {
            $buff = $tpl;
            $buff = str_replace("{date}", langdate('d.m.Y', $row['history_date']), $buff);
            $buff = str_replace("{time}", langdate('H:i', $row['history_date']), $buff);
      $buff = str_replace("{comment}", $row['history_text'], $buff);
            $buff = str_replace("{comment_shot}", strip_tags($row['history_text']), $buff);
      $buff = str_replace("{plugin}", $row['history_plugin'], $buff);
      $buff = str_replace("{plugin.id}", $row['history_plugin_id'], $buff);
            $buff = str_replace("{user}", $row['history_user_name'], $buff);
      $buff = str_replace("{user_urlencode}", urlencode($row['history_user_name']), $buff);
      $buff = str_replace("{sum}", $row['history_plus']	? "<font color=\"anal\">+{$row['history_plus']} {$row['history_currency']}</font>"
                                    : "<font color=\"red\" id=\"net1\">-{$row['history_minus']} {$row['history_currency']}</font>", $buff);
            $widjet .= $buff;
        }

He, from the _billing_history base, displays all sorts of values. And I need to make a request and a tag to display a response that would display exactly the number of records in this _billing_history database. Ie For example: "Total records {zapisi}" and the tag displays the number of records in this database.
Thanks in advance!