Frank

From Memory Alpha, the free Star Trek reference.

In an illusion experienced by The Doctor, Frank was the name of Reginald Barclay's cousin.

In 2371, The Doctor experienced a series of illusions, including one in which Reginald Barclay appeared, claiming the Doctor was really Lewis Zimmerman and the crew of USS Voyager were merely holograms. Barclay claimed to be the one who programmed the holograms and that he modeled the character of Tom Paris after his cousin, Frank. (VOY: "Projections")

Because Barclay was really an illusion himself, it is not known whether or not he really did have a cousin named Frank.