Perhaps this could be Col Chas. A. L. Lamar of the 26th [Lamar's] Georgia Infantry, afterward Lt Col Lamar's 7th Infantry battalion, which later merged into 61st Georgia.

See also: OR Vol VI, p. 386 for a reference to LtCol Lamar's batalion as follows:

HDQRS. MILITARY DISTRICT, DEPT. OF GEORGIA,
Brunswick, February 16, 1862.
Captain T. A. WASHINGTON,
Assistant Adjutant-General:
CAPTAIN: I have the honor to report, for the information of General Lee, that the guns have all been removed from the islands and brought to this place, with the exception of one 32-pounder, which I expect up in the course of the day. One 42-pounder and eight 32-pounders have been shipped to Savannah by rail, and I hope to get off to-day and to-morrow the columbiads and the remaining 32s, reserving four 32s to be sent to Fernandina. Lieutenant-Colonel Lamar's battalion is now encamped at this place, and Colonel Styles' command, it is hoped, will all be withdrawn before to-morrow night, though the weather is now very unfavorable, especially for the removal of his horse company and light artillery.
Before finally evacuating this position I beg to bring to the consideration of the general the question of burning the town of Brunswick. For the moral effect it would produce upon the enemy, as evidencing our determination to continue the present contest with unconquerable determination and at every sacrifice, and for other obvious reasons, which you will think it needless for me to recite, I would respectfully urge that I be furnished with precise orders to destroy all the buildings that can afford shelter and comfort to the enemy. I desire also again to request of the general that I may be allowed to bring back Blain's company from Cumberland. The captain and colonel are both anxious that this company should not be withdrawn from my command, and its anomalous position will be fruitful of embarrassments, without, as it appears to me, any corresponding benefit. In this connection I would respectfully submit that General Trapier is much better able to supply a garrison for Cumberland than I am to spare a good company from this military district.
I am, captain, very respectfully, your obedient servant,
H. W. MERCER,
Brigadier-General, Commanding.