Using the search you can find a few entries about Curl in Perl: Curl and Perl Correct way to POST with Perl Curl?

In your case, you need to add your parameters to $string

$string = "level=2&pass=pwd&form-id=user_login&op=Log in";
$string_length= length($string);
$curl->setopt( CURLOPT_POSTFIELDS, "$string" );
$curl->setopt( CURLOPT_POSTFIELDSIZE, $length );
$curl->setopt( CURLOPT_POST, 1 );
$curl->setopt( CURLOPT_CONNECTTIMEOUT,8);
[download]

as shown in the last post. Good luck!

Click for a complete list of options you can set.