Nope, all Greek, omicron omega nu.
Of course, Christ, the Existing-One (to translate the Greek, or its Hebrew equivalent YHVH) into English, is the same person as Jesus Christ. Quarrelling about folks who have, at one place, expressed sound Christology, confessing Christ to be one person in two natures, at once fully human and fully divine, at another making a linguistic distinction when speaking of Him before His Incarnation by using only phrases and words which refer to His divine nature is a bit odd and not very fruitful.
The fundamental private prayer in Orthodox Christian spirituality is "Lord Jesus Christ, Son of God, have mercy on me a sinner." (Though shorter versions are also used, including even the simple repetition of the name "Jesus").
I think you mean: יהוה