Hi Arun,
What I think, you are trying to calculate and post interest during invoicing.
And, you want to calculate interest on all open and overdue invoices. In this case you can use below enhacement:
FQEVENTS: R402.
Read all open items and call FM FKK_GNRLITEM_POST_INTEREST_DOC to calculate the installment.
This should be able to post the delta interest (IT document).
And for clearing and bill print out, you can maintain the Main and SUB in below configuration:
Maintain Transaction for Account Maintenance
Maintain Transaction for Bill print out.
Below is the SPRO path:
SAP Customizing Implementation Guide -> SAP Utilities -> Invoicing -> Invoice Processing -> Item Selection in Invoicing -> Item Selection in Account Maintenance/ Define Sub-Items.
Please let me know if this does not work.
Thanks,
Bodhisattwa Roy