BUS2105-ReleaseStepCreated

I have a workflow for purchase requisition approval triggered by: BUS2105-ReleaseStepCreated.

This means that the approval is item-wise.

I have a requirement that in the case of a cost center registered on more lines than one, these should be summed up and sent to the correct approver.

Example:

Purchase requisition with items:

10 CC 123 Amount 2000EUR

20 CC 765 Amount 1500EUR

30 CC 123 Amount 4000EUR

In this case item 10 and 30 are to be summarized since they have the same cost center (123) to 6000EUR and there should in this case only be started 2 workflows. One with item 20 - amount 1500EUR and one with items 10 & 30 for the approval amount 6000EUR.

Is this at all possible??