Yes. Every EU country is party to the Hague Apostille Convention, so your notarised power of attorney needs an apostille rather than embassy legalisation. Most authorities will then ask for a sworn translation, which in Spain means a traductor jurado accredited by the Ministry of Foreign Affairs, not simply a competent bilingual translator.
There is a way to keep that cost down. When you ask your lawyer abroad for the wording, ask whether they can supply it bilingually. If the power of attorney is already in English and Spanish, only the notarial certificate and the apostille need translating, which is a small fraction of the text and a small fraction of the fee. The translation still has to be done after the apostille is attached, so that the apostille is covered too.
We can notarise, apostille, and arrange a sworn translation together.