As always the answer is found using perldoc : perldoc perlre


Use \Q or quotemeta().
This way '(' won't be interpreted as the first parenthesis enclosing backreference...

UPDATE:

I remove perlre quotation (youll have to read it all ;-)
Beccause of Vynce's answer which I didn't see while I was submitting this one...

"Only Bad Coders Code Badly In Perl" (OBC2BIP)