Mr. and Mrs. Alan P. Pohlman of Wyckoff, N.J., announce the engagement of their daughter, Karen Lynn Pohlman, to Shawn Eugene Quill, son of Mr. and Mrs. Charles G. Quill of Olive Branch, Miss., formerly of West Seneca. A June wedding is planned. The bride-elect, a graduate of Ramapo High School, Franklin Lakes, N.J., and Dickinson College, is completing a master's degree in New York University. Her fiance, a West Seneca East High School and Dickinson graduate, has a master's degree from the American University. He is a consultant with Arthur Andersen, New York City.