See...
12th Battalion
Confederate Guards Response Battalion
Guide to Louisiana Confederate Military Units 1862-1865... Arthur W. Bergeron Jr.
Also, please read this post...
http://history-sites.com/mb/cw/mscwmb/archive_index.cgi?noframes;read=750
and this post...
http://history-sites.com/mb/cw/mscwmb/archive_index.cgi?noframes;read=743