You needn't change the split, but you could use a array slice in on the loop (only get the first and fifth column):

my $row = 0;
while (<TABFILE>) {
  chomp;

  my @fld = split /\t/;
  my $col = 0;

  foreach my $token (@fld[0,4]) {
    $worksheet->write($row, $col, $token);
    $col++;
  }

  $row++;
}
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