XLSperl -lane 's/fubar/foobar/ for(@F); XLSprint @F' < old.xls > new.xls

##</code><code>##

XLSperl -lne '$h{"$WS:$CELL: $_"}++;END{print for(grep {$h{$_}==1} keys %h)}' old.xls new.xls

##</code><code>##

XLSperl -lne '$h{"$WS:$CELL:$_"}.="in $ARGV";
  END{print "$_ ($h{$_})" for(grep{$h{$_}!~/\.xlsin /}sort keys %h)}' a.xls b.xls