I do not comprehend some of the military termenology but I will tell you where I got my information. There were many companys in the 38th Regiment and Elias Dupree was in Company I which was formed in Dawson County. There is a book (consisting of many different volumes). Title is "Roster of Confederate Soldiers of GA" the roster was compilied by Lillian Henderson. I think the library number is E 559. If your local library does not have these volumes, they may be able to get the one you need on interlibrary loan. The book gives muster roll information by company.
I hope this information is of some help to you.