Complex sentence: Milliken returned to Nebraska in 1988 where he accepted the position of executive assistant to the president of the University of Nebraska, and he was subsequently appointed Secretary to the Board of Regents and Vice President for External Affairs.
Split into simpler sentences: Milliken returned to Nebraska in 1988 as executive assistant to the president of the University of Nebraska. He was subsequently appointed Secretary to the Board of Regents and Vice President for External Affairs.