Solution : https://service.sap.com/sap/support/notes/692652 (SAP Service marketplace login required)
Key words : 
ipc installation directory/lib/userexits folder, refer vertex/taxware documentation, pricing procedure customizing passes, pricing customizing offers subtotals 1-6, ipc installation guide, //              call formula 500// set data, //    fill gross amount      pricingitem, //    fill freight amount     pricingitem, vertex/taxware/sabrix, pricing procedure customizing
Related Notes : 
       
| 673222 | Tax interface: Sending additional fields (formula 300) | 
| 486061 | How to get patches for CRM Internet Pricing Configurator |