ahh, currently i don't think there is support for it any more. I laoded up teh data files for the previous versions of warhammer included 6th, 7th, adn 8th and checked the allowable rulesets for each and non of them included ravening hordes.
I'll check adn see if i can locate a warhammer 5th edition data file adn see if it was included in there.
Update:
I have found the old Armybuilder 5th edition files for fantasy. They are located here:
http://www.datafilecentral.com/ab/warhammer_v2.ab
The only downside is this: It is only compatable with Armbuilder versions 2.X and I was unable to get it to laod for versions 3.X However if you happen to ahve an old version of armybuilder available it should work fine.