>perl -wMstrict -le
"my $line = 'One two three four five';
 if ($line =~ m/(one)\s(two)\s(three)\s(four)\s(five)/i){
   my $neo;
   { ($neo = $1) =~ s{ (o)(ne) }{$2$1}xmsi; }
   print qq{neo '$neo'};
   print qq{1: $1};  print qq{2: $2};  print qq{3: $3};
   print qq{4: $4};  print qq{5: $5};
   }
"
neo 'neO'
1: One
2: two
3: three
4: four
5: five