Looking for a book about werewolves and The Spear of Longinus

[mojojojo]

Several years ago I bought a paperback novel from a used bookstore.
Unfortunately I lost it soon after. It was set in the WW2 ear and it had
something to do with an an evil Asian monk who had green hands (at one point a character to them as "Little Green Monkeypaws") that was using
the Spear of Spear of Longinus for nefarious purposes. An American detective
(who was also a werewolf) was trying to stop him.

Does any one have any idea what this book was?
It was a paperback and there was a picture of a wolfman type werewolf on the cover.

[Moonlord]

Was he a Nazi spy hunter? I remember something like that from the 80s with the Spear of Longinus and a werewolf detective, but can't pinpoint the name. I will keep looking for it.