Project invoices using events

Hi,

We have to migrate 500+ Project's open customer invoices. For doing this we will be loading project billing events, using client extensions we are creating the invoices in approved and released status.

Our requirement is to have one invoice for each event of a project. We are uploading events with different Event dates.

But a run of Generate draft invoices creates one customer invioce for all the events of a project till Bill through date.
Since the number of invoices is huge we are finding it difficult to meet the requirement of having one customer invoice for each event.

Please share your experience on how we can meet our requirement using any other client extension!!!.