Good, I found Thomas Burton Wilkerson, Assistant Surgeon, 2nd Corps., Army of Northern Virginia, posted at Winchester, Va. October, 1862, Hospital 2nd Army Corp., Orange C. H. Sept. 7, 1863

You’re correct, the clerk transcribing the Surgeons certificate must have mistaken Core for Corps.

I would assume the Corps. hospital would be removed from time to time as their Headquarters re-located and could be considered a Field Hospital?