Just off the top of my head, the ranking foreign born officers of an Alabama regiment would be Colonels Stephen A. M. Underwood of the 65th Alabama (Scotland) and James Hagan of the 3rd AL Cav (Ireland). German-born John P. Emrich rose to Lt. Col. 8th AL Inf.
Technically, after secession, northern-born Alabamians were "foreign born" also. These would include NY-born Brig. Gen. Archibald Gracie.