In the view of the Church, a civil divorce is a legal separation done for the purposes of protecting personal safety, settling mutual finances, and determining the custody arrangements for minor children:
The separation of spouses while maintaining the marriage bond can be legitimate in certain cases provided for by canon law.
If civil divorce remains the only possible way of ensuring certain legal rights, the care of the children, or the protection of inheritance, it can be tolerated and does not constitute a moral offense (CCC 2383).
Assuming that these ends enumerated by the Catechism of the Catholic Church are the ends to which the Catholic lawyer is working in the divorce cases that he accepts, yes, he may handle such cases.
DISCLAIMER: Catholic Answers has turned over the archive to Catholic-Questions.org and no longer owns, manages, or moderates the forums. For additional apologetics resources please visit www.catholic.com.