Missing costomer account in reconciliation for A/R rebate provision account

Hi,

I have a question regarding rebate corrections. In rebate correction's accounting document, there are no customer account and only 2 G/L accounts. One is A/R rebate provision, another is deductions for rebate. So when accounting department do the reconciliation on profit center lever via KE5Z, they cannot see customer account associated with G/L accounts in report because there is empty in customer field of accounting doc's line item. FI/CO consultant tried to use substitution rule to get the customer number, but it wont work.

Can anybody have idea to show the customer account in KE5Z's report? And which way should we go, SD or FICO?

Thanks in advance,

DL