Extracting Quotations without line-items with DatSource 0CRM_QUOTA_ORDER_I

Hello Experts,

The CRM DS 0CRM_QUOTA_ORDER_I extracts only those quotations for which a line item exists. Is there a way to extract Quotations *without* a line item using the same DataSource?

I'm aware that I can use a header DataSource to extract the records, but I have to stick with this one because the data-flow from 0CRM_QUOTA_ORDER_I to the cube is already set up and being reported on. It has a number of routines which I'll have to write all over again if I go with a different DataSource.

Thanks.