Lispers have traditionally eschewed regular expressions but the truth is that they are often useful and sometimes the most practical way to deal with a problem. Because of the bias against regular expressions, the CL specification does not include them.
Happily, there is a de facto standard implementation: CL-PPCRE written by Edi Weitz. Now Weitz is writing a book on Common Lisp. Amazon is claiming it will be released in December by Apress. It will be a collection of Lisp recipes.
As someone who has used many of Weitz’s libraries—especially CL-PPCRE—I am really looking forward to the book. Weitz is a master and we can all learn a lot from him.