There are several correspondence between Beauregard, Johnston, Holmes and Confederate Secretary of War Randolph in Oct. Nov. and Dec. of 1862 in the O.R.'s dealing with the several permutations of plans to transfer trans Mississippi troops and eventually Garlands Brigade east even as far as to Virginia.
In fact of matter that is one of the main reason that I believe that Holmes was sent west to relieve Hindman in command of the Trans Mississippi Department was to aid in transferring more of the troops raised in the Trans Mississippi Department to the eastern theaters.