Calculate Charges in FT in R11 in a validation rou

Hi Colleagues: I want to get the charges/commissions values in an FT using a VALIDATION ROUTINE. The reason to do this, is the inputter has to be aware of the final amount that will be credited to the credit account. I have to suppose that the charges codes are already in R.NEW and I just want to trigger the routine that calculates this charges. We have R11 Desktop version. Thanks for your help.

Use CALCUATE.CHARGE API