As I mentioned when looking for the 166th CIC Detachment, a lot of this material has not been declassified. However, here are a few suggestions.
Within Record Group 319 (Records of the Army Staff), Command Reports Files of the Counterintelligence Corps might have what you're looking for.
Additionally, there is a series of Organizational History Files that are the right time period. A majority of these records have been declassified, however, they are restricted for personal information under FOIA (b)(6). Since the series is unprocessed, you would want to contact Archives2reference@nara.gov to better ascertain whether this series has what you need. If it does, the Reference Staff can walk you through filing a FOIA request. You can find more information about FOIA at the National Archives here: FOIA Reference Guide