my $sortscheme = sub { my @flds_a = split(/,,/, $Sort::External::a);

                  my @flds_b = split(/,,/, $Sort::External::b);

                   $flds_a[0] cmp $flds_b[0]; };

##</code><code>##

my $sortscheme = sub { substr( $Sort::External::a, 0, 25 ) cmp substr( $Sort::External::b, 0, 25 ); };

##</code><code>##

perl -nle"print substr( $_, 21 ) . substr($_, 0, 21 )" dataf 
| \windows\system32\sort /M 5242880 /+62 
| perl -nle"print substr($_,62) . substr($_,0,-21)" > dataf.sorted