Complex sentence: The producers wanted to hire an actress that could portray B'Elanna's inner struggle between her human and Klingon halves, and when Roxann Biggs Dawson read for the role, she became the first member of the Voyager actors to be cast.
Split into simpler sentences: The producers wanted to hire an actress that could portray B'Elanna's inner struggle between her human and Klingon halves. After Roxann Dawson read for the role, she became the first member of the "Voyager" actors to be cast.