PO in R/3 to take SC currency?

We are on SRM3.0 (SP11) , CLASSIC SCENARIO.
Currently, when I create a PO for SC line item having currency GBP --> the PO is created with line item currency EUR. This is because the vendor currency in R/3 is maintained in EUR.
Is there a BADI/User Exit in SRM/R/3 through which I can ensure that the PO gets created in the SC currency.
Is it possible to put any checks etc. like for specific Purchase organizations the PO should be created in SC currency and for others it should get created in Vendor currency.


We have handled this several times.
<u>Use any of the BADIs using SE18 Transaction.</u>
Exit while creating a purchase order in the backend system
OLD Exit while creating a PO in the backend system      
ECS: PO Transfer to Logistics Backend                   
Hope this will help.
Please reward suitable points, incase it suits your requirements.
- Atul