German A Level in Wales?

Hey,

I'm currently studying Psychology, ICT, RE and Business Studies in sixth form, and I've decided that I also want to study German. MY school doesn't offer an AS/A level German course.
I'm already halfway through Year 12, so obviously I can't start now. I was wondering however, if I could join a German AS course in another school while I'm in Year 13 in my current school? I'm thinking of dropping one of my AS subjects in exchange for German.
Another question: Would it be possible for me to study the A Level German course during my gap year? Obviously there are some things that could affect this, e.g. lesson times clashing in either school, but I was wondering if this would be possible at all, assuming there are no lesson clashes. Also, the school that offers German isn't too far from th school I'm currently in, so transport shouldn't be an issue.

Any help/advice/suggestions would be brilliant, as I want to get this organised ASAP. Thank you!