In our opinion, Jesus Christ is in the Old Testament to that degree in which true and obedient Israel took shape. He fulfilled by his obedience to the will of God the task unfulfilled by Israel. However, the humanity of Jesus Christ was prefigured to that degree to which Israel did respond in obedience. In the institutions of Israel, as well as in the prophets, the "Suffering Servant," the "I" of the Psalms, a reality appeared which found its wholeness in Christ. The New Testament goes far beyond the point of understanding the work of Christ in the Old Testament merely in terms of his role as the Eternal Word. Rather, the humanity of Jesus Christ, who is true Israel, was forming itself in the Old Covenant [*].I should point out here that Glen, author of the Barthian blog Christ is the Truth, has a thread dealing with Christ in the Old Testament. Given the Barthian flavour of this quote as well as most of Childs' theology, I hope to find time to read this series in order to help me grasp Childs' theology better.
Go here for Wilhem Vischer's approach.
[*] B.S. Childs, "Prophecy and Fulfillment: A Study of Contemporary Hermeneutics," Interpretation 12 no 3 (1958), 270, 1.