Create Tax Rule for AP invoice type (Goods or Services)

Hi,

As per 'Spanish Modelo 349 – ESL / EPL Changes, Release 12 (Doc ID 1145773.1)' I need to assign Tax Reporting Type (Services, Goods or Triangulation) for invoices. Since we have a single Tax rate for a country and Entity, I need to create a Tax Rule that would automatically assign Tax Reporting Type (S, G or T) for AP invoices. I found several Oracle notes related with Tax Rules, but there is no specific case for my situation. I understand that I could use Invoice Line attribute 'Product Type' for creating Tax Rule, but I need guidance to make it in reality.