Mary L. Fortner, daughter of Charles and Teresa, placed this ad in the Confederate Veteran Magazine.
http://books.google.com/books?id=ZEEOAAAAYAAJ&pg=PA242&lpg=PA242&dq=charles+d.+fortner&source=bl&ots=mhMvQLvycr&sig=r36aUJxOE66FF3Ldhazm1q2f_ew&hl=en&ei=H-COSoijG4q6lAeRjNC8DA&sa=X&oi=book_result&ct=result&resnum=9

In this ad she mentions Capt. Joe or Jesse Glenn, this leads me to believe Charles D. Fortner enlisted first in CO A, 36th. Georgia Volunteers and apparently transferred to the 52nd. Georgia.

Here's a muster roll for CO A, 36th. (Broyles') Georgia Infantry.
http://files.usgwarchives.net/ga/whitfield/history/other/gms362historyo.txt

Hope this helps and good luck with your research.
Mitchell Sanders