Hi Robert,

I confirmed I can make like this :

SELECT Semaine, SUM(Dicos) AS Dictionnaires, SUM(Gen) AS Généralités, SUM(Philo) AS Philosophie, SUM(Religion) AS Religion, SUM(SHS) AS SHS, SUM(Sciences) AS Sciences, SUM(Tech) AS Technique, SUM(Arts) AS Arts, SUM(Litt) AS Littérature, SUM(HisGeo) AS "Histoire - Géographie"
FROM (
SELECT 
{fn WEEK(rcddate)} AS "Semaine",
CASE {fn LEFT(cot,1)}
WHEN '(' THEN 1
END Dicos,
CASE {fn LEFT(cot,1)}
WHEN '0' THEN 1
END Gen,
CASE {fn LEFT(cot,1)}
WHEN '1' THEN 1
END Philo,
CASE {fn LEFT(cot,1)}
WHEN '2' THEN 1
END Religion,
CASE {fn LEFT(cot,1)}
WHEN '3' THEN 1
END SHS,
CASE {fn LEFT(cot,1)}
WHEN '5' THEN 1
END Sciences,
CASE {fn LEFT(cot,1)}
WHEN '6' THEN 1
END Tech,
CASE {fn LEFT(cot,1)}
WHEN '7' THEN 1
END Arts,
CASE {fn LEFT(cot,1)}
WHEN '8' THEN 1
END Litt,
CASE {fn LEFT(cot,1)}
WHEN '9' THEN 1
END HisGeo
FROM BCSCAN)
GROUP By Semaine

Sorry for the long time for the response... I've lost my tourist visa "Server Administrator" for two weeks at my job because security reasons and it's not completely resolved...

Many thanks