How to read the account assignment details of a service PO?

Hello Gurus,

I am trying to park an MM invoice via MIRO using BAPI_INCOMINGINVOICE_PARK and for a 'SERVICE PO', I need to fill in the Header data, Line item data with the service entry sheet number and also the accounting assignments for the line item. I am using the BAPI_PO_GETDETAIL to get the service entry. This BAPI also gives me the acct assignmnets but doesn't give me all the account assignments for a line item. Is there a way or a FM I can use to read the account assigment for a service PO line item with the amount?

Thanks