Enhancement for Accounting Release through VF02

Need Enhancement (Exit / BADI) for VF02 Accounting Release

we need to change ex.rate for a specific condition type.

Right Now, system is converting Amount in LC using VBRK-KURRF for All the conditions of VF02.

But we need to convert Amount In LC for GST related condition by different Ex.rate.

Please help me to find out appropriate enhancement.