Story Hooks

Hmm, yeah that wouldn't really work for him that way. That vamp fully stands behind his actions. I was thinking they would have to research the vampire itself, which would involve interrogating his spawn and following up to the civilization which initially sent them out on their colonization mission. Having to dig deep into shameful dwarven lore, histories that are buried in their royal library which only a trusted few have access to.
So they'd have to either do some major butt-kissing to that Dwarf king, or break into the library's lower levels, to find the book which details the creation of the the vampire. Then work their way to that temple, which is undoubtedly guarded by undead minions at that point, and been thoroughly desecrated over the years.
Now that sounds like a plan to destroy just the vampire's hand. Excellent idea. But how does a party consecrate a temple to a god that is dead and presumably has no more worshipers. A standard consecrate spell only works for the caster's religion. Now if the god died by other means and there is an isolated cult that still worshipers her then that could be a plan. Get the hand away from an evil NPC who is using it. Find out about the vampire's anger at the previous god, find out about the god being dead, find out about an isolated cult to the god, probably of elves, take the hand there, create a new temple to that god and have a cleric of that god cast consecrate on the temple. Then have that same cleric or another one (regardless of that cleric's religion) cast break enchantment on the hand, all while having to fend of the vampire. Now you have a campaign.