read this one:
http://www.regular-expressions.info/characters.html#qe"Escaping a single metacharacter with a backslash works in all regular expression flavors. Many flavors also support the \Q...\E escape sequence. All the characters between the \Q and the \E are interpreted as literal characters. E.g. \Q*\d+*\E matches the literal text *\d+*. The \E may be omitted at the end of the regex, so \Q*\d+* is the same as \Q*\d+*\E. "
regards.