I guess you are looking for 4.6 A simple HTML+ converter example.You can pass your $para to your function like this.

XML::Twig->new(
    twig_roots => {
        'div' => sub{ &div(@_,$para); },
    }
)->parsefile("my_file");
[download]

and use it in your function

sub div {
  my ($t, $elt,$para) = @_;
...
[download]

I hope I understand your intention...