Glen, His correct name in my opinion was David Duff Cochran and his records can be found on fold 3 under David D. Cockram with the 5th Kentucky Mounted Infantry.
Like your ancestor whose information was with the 41st Georgia Cochran's was with the 5th Kentucky Mounted Infantry.
Pleasant Cockerham is an entirely different soldier.
D. D. Cochran was captured June 9, 1863 at Monticello, Kentucky. He was with reporting in Company K of the 10th Confederate Cavalry. If this is correct then perhaps other companies of the 10th Confederate Cavalry were also at Monticello in early June of 1863.