After much wrestling, mainly through my misunderstanding of the Net::FTP module, I have arrived at the following script, which does what I need. I post it here as 'closure' - in the hope that it may be useful to someone else... (multiple file downloads tomorrow :))

#!/usr/bin/perl -w
use strict;
use Net::FTP;
use CGI::Carp qw(fatalsToBrowser warningsToBrowser);

my $home="mysite.com";
my $username="username";
my $password="password";
my $directory="data/edit";
my $filename="data.txt";
my $filename1="path/to/file/data.txt";



my $ftp = Net::FTP->new("$home")    or die "Can't connect: 1 $@\n";
$ftp->login($username, $password)       or die "Couldn't login - 1\n";
$ftp->cwd($directory)                   or die "Couldn't change direct
+ory - 1\n";
$ftp->get($filename, $filename1)                    or die "Couldn't g
+et $filename - 1\n";
my @lines = $ftp->ls("/data/edit");

$ftp->quit;

print "Content-type: text/html\n\n";
print "<br>@lines<br>";
[download]