If you're looking for a full-time staff position, it's very tricky. However, if you're looking for freelance work, you have more options.

You only need to be a traductor jurado for certain types of work. Translation agencies in Spain can use freelancers from outside the E.U. (therefore not sworn translators in Spain) for jobs not related to legal cases, government work, etc.

Register with as many agencies as possible both in and outside of Spain. Thanks to the internet, the translator, agency and client can be in three different countries. Don't forget to try out the online communities for translators as well (proz.com, translatorscafe, etc.) You also might want to subscribe to Spain-based listservs and online newsgroups related to translation. People often post jobs for freelancers.

Good luck.