Need to change price difference accounts at the time of MIRO posting

Hi,

I have a peculiar business requirement to change the price difference account to a different GL account at the time of MIRO posting. This is because the users want to reclassify the price difference amount to a different price difference account depending on some criterias which will be known only during the time of MIRO posting.

For example :-

Price difference account setup in the OBYC PRD settings :- 210450

At the time of MIRO the system will propose it this way :-

Vendor Credit : -$1200

GR/IR Debit : +$1000

210450 Price difference account debit : +$200

Now the requirement is to change the 210450 to 213000 P&L account but still retain the PRD transaction key code for the new 213000 account. It is important to retain the PRD transaction key code for this line item posting so that the system can actualize the price difference amount from the new 213000 account into the material costs. The PRD transaction key that i am talking about is this one below :-

I know this is not possible in standard SAP, as such is there any user exit to change the price difference account to a different one on the fly at the time of posting? If yes please tell me.