Back in the days there used to be a tutorial in a now closed forum ...
I used this, saved as a file called "_mulligan.txt" in the directory with the file "_carddb.txt":
Quote:
hold;pala;warlock;CS2_093:1
hold;pala;hunter;CS2_093:1
discard;pala;warlock;EX1_360,EX1_362,EX1_382;3
discard;pala;all;EX1_360,EX1_362,EX1_382;4
discard;warlock;all;CS2_188,CS2_203,EX1_308;4
It means: as paladin against warlock or hunter keep one copy of consecration or
as warlock against all classes discard some cards and all that cost more than 4 mana
(maybe it was 4 or more mana, i don't remember exactly), and so on.
The only class that is abbreviated, is paladin as "pala". The card names can be taken
from "_carddb.txt". Hold has priority over discard (or maybe it was because an earlier
line has a higher priority).
I don't know, if it is still working, but give it a try.