Hello there, @Adam Donaldson.
In QuickBooks Desktop, you can import vendor bills using IIF files.
Now, if you wish to import the total amount, net amount, and VAT for a bill, you can continue doing what you have been doing. This is the only option to complete the task that you want.
Otherwise, you can check for other third-party apps to help you with importing bills. To look for an importing tool using Desktop, click on this link: QuickBooks third-party apps.
In addition to that, let me share these articles to help export and import data in QuickBooks:
Fill me in if you have other questions about importing bills in QuickBooks. I'll be happy to help you. Stay safe and have a good day!