I know I've ran across this in one of my 3.5 books recently and I cant remember the book or much about it, and am having trouble re-locating this. There was an entry towards the front of the book for a vial of vampiric blood. It gave similar stats as a barbarians rage but you were also considered under the control of the vampire while its effects lasted.
About the book: If i recall correctly, the book was focused more on monsters; but not the monster manual. I believe the passage where it talked about the vials was also talking about how a vampire could make a human its servant without changing it to a spawn or charming it. I really cant recall much about the book itself... i believe it was in one of the thinner books ( <250 pages) but i cant be sure as I've spent three days going through these books now and cant locate it.
If it helps my 3.5 collection consists of : Exalted Deeds, Vile darkness and VD more archfiends, Complete adventurer, complete arcane, complete divine, complete warrior, draconomicon, DMG, PHB, Monster Manual, Expanded Psionics, Ghostwalk, and Unearthed Arcana.
And i also have other books, incase I'm wrong about it being a 3.5 thing... Monster Manual 2, tome and blood, sword and fist, song and silence, oriental adventures, Masters of the wild druids grove and MotW barbariands druids and rangers, manual of the planes, fiend folio, Defenders of the faith, arms and equipment, and... uh.. the book of erotic fantasy. =)
I know that its a long shot for someone to pin-point this as I'm having issues finding it with my books in front of me or with google... but I appreciate any information or help on finding this ruling.