Theresa --

It appears that C. C. Wilson was the first colonel of this regiment, elected to this office when the 25th Georgia organized. Someone else was elected lieutenant colonel, so it seems unlikely that he would ever have held that rank in Confederate service. Possibly he was a lieutenant colonel in the Georgia militia before becoming captain. That's the only explanation I can imagine.

Records of promotions, including dates of appointment or election, rank, and acceptance are often found in military service files. Wilson's service file(s) should contain quite a number of documents.