Thank you for your question
My name is ***** ***** I shall do my best to help you
Yes it is possible to do that - but on a practical basis it is not entirely realistic since the idea is that there is someone who can deal with matters on your behalf - difficult if they are living abroad.
It would be better to appoint two people - the one in Spain and one in the UK who can work together or separately as needed
Please ask if you need further details