Cool thanks all. Here's a snippet of what I ended up with...
## get the edit_dns page dump the current contents of the
form to a file
my $name = 'form_zone';

my $response = $ua->get(EDIT_DNS);
my $form = HTML::Form->parse($response->content,EDIT_DNS);
my $value = $form->value( $name );
## check the contents of the dns text area
#print $value;
## make a backup of the content
open BACKUP, "> dns.backup.txt";
print BACKUP $value;
close BACKUP;
## this is the file we muck with
open DNS, "> dns.txt";
print DNS $value;
close DNS;