Return wp_pagenavi()?

Is it possible to return the value of wp_pagenavi instead of echoing it? I’m trying to get pagination working in a shortcode that lists posts from a custom post type.

The following code adds pagination to the page and it functions, but since shortcodes don’t support echoing code, it places the pager outside the html structure:
wp_pagenavi( array( 'query' => $query ) );

Is there another function to call, or some other workaround, for this purpose?

Many thanks.