Selling my home - is the law for getting a discount using the 11.11% law still valid?

[dickuk]

Hi
I have owned a property in Spain since mid 1987 which I paid the equivalent of £26,000 for (in pesetas at the time).
I am looking to sell this year for approx 170,000 euros.
I realise that I have to pay 19% CGT on some of this, but can I apply the 11.11% rule (adding up to 77.77% I think for 9 years 1987 - 1996) to this to reduce it further? If so, does this 77.77% apply to the whole amount or just on a part of it?
Also, how do I convert the £26,000 that was in pesetas into euros to calculate the original purchase price in euros?
Many Thanks
Richard