Maximum total exposure (A/R+Open order value) per customer per period

I am looking for a field in a file that would record the total maximum exposure (Open receivables + open order value) on a periodic basis.  I see the total exposure field displayed on the Account Status screen but believe this is calculated "as of" the time it is reviewed and the data is not written anywhere.  I am being asked to write a report comparing the total maximum exposure per customer against their credit limit for the past period. I looked in the documentation and was unable to find anything.  Any help is appreciated!