in reply to Removing dot before cookie host/domain URL

You are on the right track. Let's give the page a name MyTestCookie.cgi
Delete the -domain=>'foobar.com', so your code looks like this: 
#!/usr/bin/perl

use CGI;
$query = new CGI;

$cookie1 = $query->cookie(
-name=>'TheCookie',
-value=>'anything ',
-expires=>'+24h',
-path=>'/',
-secure=> 0);

print $query->header(-cookie=>$cookie1);

print"<html>
<body>
Done.
</body>
</html>";

print $query->end_html

[download]
Then load the page (and cookie) without the 'www' in the URL:
http://foobar.com/MyTestCookie.cgi

That should do it!

In Section Seekers of Perl Wisdom