c:\@Work\Perl\monks>perl -wMstrict -le
"my $field2_b = 'abcd';
 ;;
 my $find1 = '%';
 if ($field2_b ne '') { s/[^$find1]?^/\^/, s/[$find1]?$/+/ for $field2_b };
 print qq{'$field2_b'};
"
'^abcd+'