display specific widget to a page

you can create new widget area.

     function header_widget_areas() {

    register_sidebar( array(
        'name' => __( 'header', 'header' ),
        'id' => 'header',
        'description' => __( 'Insert something for about us text.', 'header' ),
        'before_widget' => '<div class="widget span3">',
        'after_widget' => '</div>',
        'before_title' => '<h4>',
        'after_title' => '</h4>',
    ) );



}
add_action('widgets_init', 'header_widget_areas');

Then place your widget in that area from appearance.
Then in your template where you want to display widget past this code.

<?php if (function_exists('header_widget_areas')): ?>

                                                <?php dynamic_sidebar('header'); ?> 
                                            <?php endif; ?>