If the values are always zero or one, then I'd cheat, a bit.
I'd create a Mapping table:
Value Result
0 N/A
1 AD
2 SL
3 SL,AD
4 EX
5 EX,AD
6 EX,SL
7 EX,SL,AD
And just use a trivial JOIN:
SELECT d.*, m.Result FROM Dummy d
JOIN MapText m
ON (d.Dm_Ex * 4) + (d.Dm_SL * 2) + d.Dm_Ad = m.Value