How to explicitly change tax code posted from FICA to FICO in a recievable?

Dear Experts,

I have a situation where my client doesnt want a specific Tax code e.g "XY" to be posted to a GL A12345.

I have made the required configuration in EK02, the new recievable takes the new taxcode "AB" . However for adjustment reversals, where the previous document had tax code "XY" but new invoice for the same posted now, the old tax code is still appearing..

I explained that, this is a standard SAP functionality of adjustment reversal where the amount posted against the old doc will appear in the new doc but with reversed amount. But still they dont want this tax code "XY" posted to that GL....

Can there is any check/config/ enhancement to change this tax code from "XY" to "AB" when posting from FICA to FIGL?

Thanks in advance,

Priyanka