I just said you 'should' be able to. Jeesus. What the hell is wrong with you?? Go pick a fight somewhere else.
There is a way to do it anyway. Don't do weapon specialities. Take the generic poison damage. Use spells or traps or whatever until you find a weapon that makes you go 'Sweet!' and then specialise. Not that difficult to figure out.

" Road rage, air rage. Why should I be forced to divide my rage into seperate categories? To me, it's just one big, all-around, everyday rage. I don't have time for distinctions. I'm too busy screaming at people. " -George Carlin