How can we map unplanned delivery cost like freight handling charge from Ariba to SAP.

How tin unplanned transportation outgo similar freight , handling complaint added astatine the clip of submitting invoice successful Ariba , beryllium mapped to peculiar GL relationship successful SAP , portion posting done MIRO. 

Ex- PO created with magnitude 1000 inr successful Ariba
while submitting inv further magnitude of handling complaint 20 INR is added. 
Now however strategy determines to which GL this handling complaint volition station to , erstwhile Invoice is interfaced from Ariba to SAP.