How to do multiple Excise invoice for single GRPO

Dear All,

I've following scenario , kindly suggest me

1) We do Purchase Order + GRPO (All Items are Exices)

2) But we  get Partial excise invoice  day by day

Example:

We have 15 items in one GRPO on 1 march, but we will get Exice Invoice for 5 Items with different Excise ref number and Tax value on 3rd march

for remaining 10 will get 7th march.

here it is Trading so Our duty payable is not fixed ,means whenever we get Excise invoice then only we have to change the tax amount.

3) So we need to do multiple Excise Invoice against single GRPO, but SAP does not allow this.

Kindly suggest any solution for this scenario , or else any other way to reach answer.

Thanks and Regards

M G Hegde