i.e. the hemorrhoid cream lol. I'm trying to say: "Has anyone seen my Preparation H?" and so far I have: "Alguien ha visto a mi Preparation H?" . Would that make sense to someone in spanish?
How about "¿Alguien ha visto mi Preparado H?".
(Note that if you are talking about an unanimated object, not a living thing, you don't use the "a".)
There is a well-known commercial brand in Spain, Hemoal. But a wider translation would be just "crema para las hemorroides".