For internal shipments it is easy enough to export the data from worldship as you suggest but these are third party shipments.
We have a custom tool that reads the CSV bills and imports them into where we need them. But the tool that UPS provided to auto download those tools no longer works.
Their API allows you to access the billing records - but not download the csv files. Our time on everest is limited - so if someone had a tool we could start with it would probably be worth the time - but to do something from scratch is questionable at this point. If we do take the project on I will reach out to you directly, thank you