You may be able to use a JC inquiry to see cases where the amount invoiced exceeds the commitment amount, and once you have gathered the commitment numbers can use the JC Committed cost status with invoice detail report (selecting Ranges to pick specific commitments) to see both the commitment and invoice information on one report.   The JC inquiry, Committed Cost, Contract Control has a BALANCE column that is calculated based on the Revised Contract minus the Amount Invoiced. If the BALANCE is negative then the amount invoiced exceeds the commitment amount. The JC Committed cost status with Detail report is found in Job Cost, Reports, Committed cost