Allocation of costs from Cost Center to CO-PA

All,

I have this scenario and would like to develop a custom program.

Requirement is to allocate cost from one cost center to multiple Profitability segments.

Source: All costs are booked to one cost center through FI. This means all cost are accumulated at one cost center and primary cost element.

Allocation: Based on some fuzzy logic we can identify the cost to be allocated to multiple profitablity segment.

What we cannot use: Standard SAP KEU5 allocation, as the tracing factor is not possible.

So here is what I am looking for. Need to use a BAPI for CO only posting, where I will credit the primary cost element and the cost center and debit multiple profitability segments through a secondary cost element which will hit a particular value field.

Cr Primary Cost element and Cost Center

Dr Secondary cost element and Profitability segment populating the desired value field

Can someone throw light if a particular BAPI exists and how I can ensure that a particular value field gets the desired posting through this method.

Regards,

Avinash