There's a whole lot of these numeral characters in unicode, for example:

http://www.charbase.com/2169-unicode-roman-numeral-ten

(even more in http://www.charbase.com/block/number-forms)

I'm not sure if Javascript matches these in its \d pattern, however, but I think that most regexp engines default to the ascii [0-9] unless you are using \p{Number}.