.NET regular expression

Question

How would I write a regular expression (C#) which will check a given string to see if any of its characters are characters OTHER than the following:

a-z
A-Z
Æ æ Å å Ø ø - '

Answer 1

new Regex("[^a-zA-ZÆæÅåØø'-]")

The [] creates a character class, then ^ specifies negation, so a character matches the class if it's not one of those listed.