CSV Shipping data from eBay to Australia Post eParcel formats (eParcel eBay experience required)

We want to be able to export sales/shipping data from our ebay store and import it into our Australia Post eParcel account to create the relevant shipping labels & picking list. Once picked and packed the tracking number from eParcel needs to then be uploaded back to the eBay system. We need to be able to catch out any shipping address errors that customers may have entered (e.g. postcode doesn't match suburb) and give us the option to manually fix/edit these before the details are imported into eParcel and before labels are printed of course. We are happy to do the export of ebay sales data on a daily basis and run it through the application if it will be easier to develop this way, but open to any ideas that may arise. I'm sure that some of you guys have already built similar or exact application in the past. The further option to be able to import sales data from other sources will also be required in the future, and will be offered to the same developer if all goes well. Note: There are solutions available online but for a monthly fee. We want a stand alone solution (Java/VB etc) that will be able to format the files correctly and import data. Previous experience in the eParcel and eBay platforms and file import export is a MUST. Please do not contact me if you do not know what eParcel is or does.