Your code works fine! I have only added a chomp but that does not really make a difference... 

#!/bin/perl -w 
use strict; 
#variables you can change to suit your needs 
my $column_separator = ","; 
my $column_number = "2";
$column_number--; 
my @lines=<DATA>; 
foreach my $line (@lines){ 
        chomp($line);
        my @columns = split(/$column_separator/,"$line"); 
        print $columns[$column_number],"\n"; 
}

__DATA__
1,2,3,4
A,B,C,D

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In reply to Re^3: Extract column of excel by hdb
in thread Extract column of excel by MynameisAchint

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