Within the Moscow Patriarchate, the Archbishop of Korsun has administrative jurisdiction over Spain. There is a church in Barcelona (Holy Annunciation, I think) (?).
Also, the Orthodox Church in Poland has parishes in Spain, but I have not yet discovered the locations. As a Slavic church, I would imagine that their services would be in Slavonic.
Are you attending the Portuguese-Greek church in Madrid or in Barcelona? If Barcelona, then perhaps my first suggestion might work for you.
Hope you can locate what you want/need!