Mislav Kovac was a male human in Starfleet in the 24th century. As of 2370, he held the rank of Lieutenant and served as assistant chief engineer of the USS Odyssey. When Chief Engineer Rodzinski was killed by Orta, Kovac was promoted to Lieutenant Commander and became chief engineer. (DS9 - The Brave and the Bold novella: The Second Artifact)
Shortly after his promotion, he perished during the Odyssey's confrontation with the Jem'Hadar. (DS9 episode: "The Jem'Hadar")