there is... you just reference the column by name
however, if you want to return the name of a column rather than the value of a column, then you have to hardcode it --
CASE WHEN s7 = 'y' THEN 's7' ELSE '' END
, CASE WHEN s8 = 'y' THEN 's8' ELSE '' END
, CASE WHEN s9 = 'y' THEN 's9' ELSE '' END
, CASE WHEN s10 = 'y' THEN 's10' ELSE '' END
) AS columns
WHERE county = 'County D'