How to pattern match using regular expression in Scala?

I would like to be able to find a match between the first letter of a word, and one of the letters in a group such as "ABC". In pseudocode, this might look something like: case Process(word) => word.firstLetter match { case([a-c][A-C]) => case _ => } } But how do I grab the first letter in Scala instead of Java? How do I express the regular expression properly? Is it possible to do this within a c