Accounting Journal Entry for free sample sales

Dear Experts,

One of our client wants to implement free sample sales activity. We have done all the required configuration in SD module regarding free sample sales.

But Accounting Journal Entry for free sample is generating as below:

Customer A/c.........Dr.

     To, Revenue A/c (Free sample sales)..........Cr.

But our client wants the accounting journal entry to be pass as below:

BED Payable A/c .........Dr.

     To, Revenue A/c (Free sample sales).........Cr.

Please guide us if any changes needs to be done in configuration and pricing procedure of free sample sales, so that we can get accounting journal entry as per our client's requirement.

Thanks in advance & Regards,

SAP SD Team