plugin.php

<?php

/**
 * Register Scripts
 *
 */
function be_register_scripts() {
	wp_register_script( 'be-shortcode', get_stylesheet_directory_uri() . '/js/shortcode.js', array( 'jquery' ), '1.0', true );
}
add_action( 'wp_enqueue_scripts', 'be_register_scripts' );

/**
 * Create Shortcode
 *
 */
function be_cool_shortcode() {
	wp_enqueue_script( 'be-shortcode' );
	return 'This is what my shortcode does';
}
add_shortcode( 'cool-shortcode', 'be_cool_shortcode' );