c:\@Work\Perl\monks>perl -wMstrict -le
"my $re_obj = qr{([0-6BS])};
 my $re_str = '' . $re_obj;
 print $re_str;
 ;;
 if ('ABC' =~ $re_str) {
   print qq{match, \$1 captured '$1'};
   }
 else {
   print 'no match';
   }
"
(?^:([0-6BS]))
match, $1 captured 'B'