If you want to accept entries with 11 digits as well as
those with 12 digits, and
you are expecting some sort of punctuation to be included
among the digits, it will be easiest to eliminate the
punctuation first, then just check the string length:
$pw =~ s/\D+//g;
$fieldValid = ( length( $pw ) == 11 or length( $pw ) == 12 );