The McKenzie Files
by Barry K. Nelson
Military SciFi, Book 1 ... Humanity's at war with a reptilian race called the Brelac, but a secret weapon - human Reploid clones programmed to serve the Brelac - have infiltrated the Protectorate. In a bid to turn the Brelac secret weapons against their alien masters, the Protectorate reprograms three captured Reploids who may be the only thing standing between humanity and total destruction.