Howdy everyone

So I'm playing the vampire side of Dawnguard now, and I'm trying to spark the radiant quests Ancient Power and Rings of Blood Magic. I remember in the Companions there and the Thieves Guild there are tricks to force the sidequest you wanted, such as saving prior to talking to a character or leaving and reentering the area, but neither of these methods have helped me get the quest I've wanted so far. Is there a way to do this in Dawnguard?