There has been a Scandinavian club for many years, and an Irish one. Also, there are the Dutch twins that come over regularly, often in a one day trip - and don’t forget the Italian lad. A really nice fella, and very passionate about the club.
the London supporters club has an international section which many nationalities and clubs are affiliated to.
Have a look at the CCLSC website. Fantastic stuff
Edit: Martcov is a member. Met him at the Cheltenham away game a couple of years. Nice chap and a proper fan.