Importing purchase payments in bulk



Does anyone know how to fill in the fields on the bulk import file for a Purchase Payment? I can do it for bank payments for likes of wages, bank charges etc that post directly to a nominal ledger but got stuck on the Supplier Payments. 

Type must be PA I'm thinking but is Account Reference the Bank code or the Supplier code? And if its one then where does the other go?? 

These are the fields

Type Account Reference Nominal A/C Ref Department Code Date Reference Details Net Amount Tax Code Tax Amount Exchange Rate Extra Reference User Name Project Refn Cost Code Refn Country of VAT Report Type Fund

Many thanks