R42800 does not use tax from pre-payment table

Hello

We are uploading orders into E1 including the tax information. Currently, we are adding the pre-payment information including the tax amount using custom program.

For example, Let’s consider E1 calculates the tax as 6% and amount uploaded into pre-payment information is $100 (record is written to F004201 by the custom program). Payment instrument used is ‘?’

Currently, when we tested this, Sales update uses the tax re-calculated from E1 which is 6% where as we wanted to use the tax from pre-payment information which is $100.

We wanted to know if there is any way for sales update to use the tax amount from pre-payment table (F004201) instead of re-calculating the tax in E1.