Hi Frank Biganski,
Under the terms of Self Assessment, we do not provide an official exchange rate and the onus is on the individual to use a just and reasonable exchange rate for each acquisition and disposal.
For your convenience, there are exchange rates at:-
Exchange rates from HMRC in CSV and XML format
and for older rates at
Foreign exchange rates and spot rates: 1 January 1989 to 31 March 2009.
You are free to use any of the supplied rates or one of your own choosing.
We cannot comment on the exchange rates required by another country.
Thank you.