Additional account assignment for posting with transaction FINT

Hi,

after the interest calculation (customer line items) I need to insert a
WBS element during tha automatic posting of the interest invoice
(revenue account).
In the standard transaction "FINT" there is no possibility to insert
WBS element, but the only additional account assignment is Cost Center
(not correct for revenue).

I need to insert a WBS element during the automatic posting through the
FINT transaction. Is there a standard solution?

Thanks in advance
Best regards

Antonio