Order by stored procedure parameter - mysql

Question

I have a problem ordering my stored procedure by a parameter given by a user, I have tried reading but the solutions I have tried won't work.
So, is there somebody who can help me? I would like it to be sorted by Type from my Group_concat. It works if I type it in harcoded, like (ORDER BY Type1, ORDER BY Type2 and so on). But I would like something like this (ORDER BY #specificStat).
CREATE PROCEDURE getSpecificStatsBySeason(IN khID INT(11), IN seasonName varchar(40), IN specificStat INT(11))
BEGIN
SET #sql = NULL;
SET #khID = khID;
SET #seasonName = seasonName;
SET #specificStat = specificStat;
SELECT
GROUP_CONCAT(DISTINCT CONCAT('SUM(IF(em.eventTypeID = ',
et.eventTypeID, ', 1, 0)) AS Type',
et.eventTypeID )
) INTO #sql
FROM eventTypes AS et, `eventType-R-kh` AS eRk, kh AS kh WHERE et.eventTypeID = eRk.eventTypeID AND eRk.kh = kh.kh AND kh.khID = #khID;
SET #sql = CONCAT('SELECT u.userID, ud.firstname, ud.lastname,', #sql,
',
IFNULL((SELECT COUNT(s.activityID)
FROM activity AS a1, signup AS s
WHERE u.userid = s.userid
AND s.activityID = a1.activityID
AND a1.khID = #khID
AND s.answer = 1
AND se.seasonName = #seasonName
AND a1.activityDate BETWEEN se.seasonStart AND se.seasonEnd
AND a1.activityDate <= NOW()), 0) AS matchCount
FROM userData AS ud, userInfo AS u
LEFT JOIN activity AS a ON a.khID = #khID
RIGHT JOIN season AS se ON se.seasonName = #seasonName
AND a.activityDate BETWEEN se.seasonStart AND se.seasonEnd
LEFT JOIN `eventMatch` AS em ON em.userid = u.userid
AND em.activityID = a.activityID
LEFT JOIN activityMatch AS am ON a.activityID = am.activityID
WHERE u.khID = #khID
AND u.userID = ud.userID
GROUP BY u.UserID
ORDER BY #specificStat ;');
prepare stmt
FROM #sql;
execute stmt;

Answer 1

Use this instead:
...
...
AND u.userID = ud.userID
GROUP BY u.UserID
ORDER BY ', #specificStat, ' ;');