It may be that your best bet lies with the National Archives and Records Administration (NARA). You can contact them via their web site...though they are usually slow to get back to you because of the volume of traffic they get.
You should ask for the unit records. Sometimes, there is a outline history of the unit, and there SHOULD be After Action Reports at the least, month by month. There also may be S-3 message logs that were kept that list and record incoming and outgoing messages. Once in awhile, the file as well. Ask what they have and request an order form. They charge for the copying.
Depending upon how specific you want to get, the National Records Center in St. Louis MAY also contain the morning reports that track the status of individuals by Company within the BN. They will not research or make copies for you, though. You would either have to go yourself or hire a researcher to do the work.