SAP CRM IPC Java Routine 300

Hi Experts

I developed new Java pricing routiine 600 in SAP CRM IPC to calculate addtional tax exemptions for the product asper the instructions given in the OSS NOTES  942308.   We are using external tax calculation system "Vertex" to calculate  these additional Tax exemptions based on the product code, Division and account class.  The Routine 600 intern calls another SAP Standard Java Routine 300 and it will pass these additional fields to 300 routine. 

Issue:  We are using same vertex system for both ERP and CRM.  But we are getting different tax exemptions when we create an order for same ship-to-party and Product & Labour line items.

Can any one help me the list of Parameters I should pass from 600 to 300..? or any code which you have already implemented java routine for this purpose..?

Thanks in advance.

Regards

Ramana