The first Louisiana lay minister that comes to mind is Felix Pierre Poche (A Louisiana Confederate: diary of Felix Pierre Poche'). Although not a chaplain, he often helped to conduct mass but it seems it was more often in the local church rather than in the field or camp. There is an interesting thesis published on the web at http://scholarworks.uno.edu/cgi/viewcontent.cgi?article=2227&context=td specifically on Catholic chaplains but goes into some detail regarding official requirements and duties of all Confederate chaplains. Another possible good source of information might be (The Spirit Divided; Memoirs of Civil War Chaplains). There are two volumes, one for the Confederacy and one for the Union.