excise invoice in USD

customer requirement is invoice should be in USD only. For that we create sales order by changing currency to USD from INR & by maintaining conversion factors in OB08. Assume 1 USD = 5O INR. Then delivery, invoice. Upto invoice duties passed are correct. But when creating deemed excise invoice duties flowed are incorrect & also they are in INR.

Eg: VA01 - 10 QTY, BASE PRICE=50 USD FOR 1 QTY. SO TOTAL=500 USD.

BED (10%) = 50 USD.

But in J1IIN, BED showing as 1950 INR. Eventhough it is in INR it should be 2500.

Second issue system not taking deemed button in utilization.

Is the excise tax in local currency have a small deviation of exchange rate of what's being defined in OB08.