In situations like this, the split function is your friend. Split can be used to separate on a variety of delimiters.

My code:

#!/usr/bin/perl
use warnings;
use strict;

while(<DATA>) {
    my @cols = split " ", $_;
    print $cols[3],"\n";
}

__DATA__
1 222 ssss 1111 fgfg
2 333 ssse 2222 dshg
3 444 ssws 3333 sjsh
4 555 wwsw 4444 skss
[download]

And the results are:

C:\Code>perl cols_print.pl
1111
2222
3333
4444
[download]

More on split:

http://www.comp.leeds.ac.uk/Perl/split.html
http://www.perlmeme.org/howtos/perlfunc/split_function.html