Cash discount in taxinn before cst

Question

Dear Gurus, My client wants cash discount in taxinn. scenario is as follows
cash discount in betwen Cst and Excise duties as follows
Basic                                             =100
Excise such as BED and Hsess      =8.24
Total +Exc.Duties                             =108.24
Cash Discount                                    =2.24
Total for cst                                    =106
4%CST                                            =4.24
Tot PO                                            =110.24
For that in  taxinn one condition is maintained before cst  and calculation is ok as per invoice.
Problem is when we do MIRO , system shows amount difference.
Why this happening?
Any solution

Answer 1

You can try this workaround....
Create a condition type and assign it to purchasing schema and to this condition type use the subtotal for eg D, E etc in which you pass this value to some variable and in Taxinn procedure you can write routine in CalType which it will copy value from this variable and assign to this condition type.
With this you can enter the percentage in purchasing schema and this will flow in taxxin  procedure.