Freight revenue is allocated by profit center, based on the number of units

Hi SAP Gurus,

I am facing one issue in sales order processing.

The Sales order is getting created through an inbound IDOC.

The data (Condtion type and Condition value) for Freight will get populated at at the header level at will get allocated to the line Items wrt quantity.

The requirement is - "Freight revenue is allocated by profit center, based on the number of units shipped".

Please let me know how to achieve this requirement.

Regards,

Bhaskar