Hi Rahul,
No, sorry. The standard code will split the documents only by currency, as far as I can see.
What you're asking for doesn't sound very reasonable, from a practical operational viewpoint, so I'm not surprised that there's no system solution.
Why can't you simply create Pre-Declarations for the relevant Delivery items manually? Surely there will be plenty of cases where items from more than one Purchase Order arrive together, either from the same or different vendors? In those cases, you wouldn't want a one-for-one creation.
Regards,
Dave