Import retail transactions from third party application to AX

Hi,

i want to import retails transactions from a staging database to AX2012 R3 tables. such as RetailTransactionTable, RetailTransactionSalesTrans, RetailTransactionPaymentTrans, RetailTransactionDiscountTrans, etc...

Do you have any idea where is placed the standard code that do this by reading the rpf file and write it to AX retail trans tables?

Thanks!