GL Discrepancy between bank balance and reconciliation

Okay FRIENDS,

So I have a client who has pinpointed a discrepancy between their GL and their bank rec.   In a prior period somehow a check ran through payables and paid off a bill but does not have a GL batch associated with the entry.   Not sure if this is data corruption or perhaps was accidently triggered using migration mode.  

Anyways, long story short, my bank recs are good by my GL bank balance is overstated.   I need to post a GL entry to bring the GL balance back in line with the bank reconciliations.  How do I accomplish this without impacting the banking module.  

Can we do this or do we need ACU support to assist?

RoperMan !