# current lvalue sub:
  (my $val = $spreadsheet->cell('C3', 'D4')) =~ s[something][else]g;
  $spreadsheet->cell('C3', 'D4') = $val;
  $spreadsheet->recalc() if $spreadsheet->autorecalc();

  # without lvalue sub:
  (my $val = $spreadsheet->cell('C3', 'D4')) =~ s[something][else]g;
  $spreadsheet->cell('C3', 'D4', $val);