You would need to modify this for the formatting you want (I split your data on whitespace, manipulate it, and then join it again with simple tabs in between), but I believe the following code is one way to do what you are asking.

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

open(my $FILE, '<', 'input_file.txt') or die $!;

my %output_files;
my $line_number = 1;
while (<$FILE>)
{
    chomp;
    my @columns = split;
    my $value = abs($columns[$#columns]);
    
    if(!exists $output_files{$value})
    {
        open($output_files{$value}, '>', "test-out-$value.txt") or die
+ $!;
    }
    my $fh = $output_files{$value};
    
    splice @columns, 0, 0, $columns[$#columns], $line_number;
    pop @columns;
    my $output_line = join "\t", @columns;
    print $fh "$output_line\n";
    
    $line_number++;
}
[download]

EDIT: Didn't notice you moved the last column to be the first column right away, updated code for that.