To add a template in another with
$template_hook add this plugin:
PHP Code:
global $template_hook;
$newTemplate = vB_Template::create('YOUR_CUSTOM_TEMPLATE');
$template_hook['your_var'] .= $newTemplate->render();
Now just print in another template:
PHP Code:
{vb:raw template_hook.your_var}
For print in all pages, you can set
{vb:raw template_hook.your_var} in navbar template for example.