I'm on patch 1.01 of hellfire and have added a text file with "cowquest;theoquest;bardtest;multitest;barbariantest" in the hellfire folder and named it command.txt but nothing changes in the game (I've also tried adding another semicolon after "barbariantest"). I can only make warrior/rogue/sorceror/monk. Googling doesnt help and I'm not sure how to get these classes to work.

Thanks for any help

Another option is using DevilutionX and go to the settings and enable it from there.
(I'm one of the DeviutionX programmers)

This is great, thanks.