In our system the calculation of Surcharge is wrong during MIRO.
So i write this issue to the SAP, the below solution is provided by them :
Use the user exit 'J_1I7_USEREXIT_PROCESS_TKOMV' to redetermine the additional VAT condition type value. This user exit will be called after the FM 'J_1I4A_TAX_CONDITIONS', where the redetermination of the VAT will take place on the basis of the changed excise duties.
So, userexit can be implemented by CMOD and SMOD, but this userexit actually a Function Module.
But now the problem is how can i implement the 'J_1I7_USEREXIT_PROCESS_TKOMV' function Module.