Surely at some time during your move into BA you will be asked to fill in your bank account details so that the company can deposit your salary directly into an account of your choosing?
At that time, simply fill in the details of your European bank account, wherever it may be. You will be too far down the induction process for this to matter to BA. Just make sure that the information you provide is very clearly written so that your well earned first cheque cannot go amiss.
