use HTML::Template;
use Captcha::reCAPTCHA;
my $c = Captcha::reCAPTCHA->new;
my $t = HTML::Template->new( scalarref => \$template_file );
$t->param( <RECAPTCHA> => "print $c->get_html( 'your public key here' );" );    
$Output = $t->output;