You could also be looking for Esteban Rodriguez, a crewmember aboard the USS Enterprise.

Rodriguez was a genetically-engineered Augment from Earth's late 20th century, a follower of Khan Noonien Singh and survivor of the Eugenics Wars. Rodriguez escaped Earth aboard the SS Botany Bay.

In 2267, the Botany Bay was discovered by the USS Enterprise, where Rodriguez was among the 72 surviving members of Khan's original group of 84. During Khan's takeover of the Enterprise, Rodriguez was in the armory. He was sent to Ceti Alpha V with the rest of Khan's people after a failed attempt to capture the Enterprise. (TOS: "Space Seed")

This character was only mentioned in dialogue.
According to the novel To Reign in Hell: The Exile of Khan Noonien Singh, his first name is Armando.