Solution - 1

Do you have access to the database? You can use PHP/WP to access the database and pull the values you need. I had a similar issue access Pinnacle Cart from WordPress a few weeks ago... this was the code I used:

global $template,$wp_query; 

	if ( is_front_page() ) { 
		$pinn_db = new wpdb(DB_USER, DB_PASSWORD, 'saddle_pinn', DB_HOST);
		
		$querystr = "SELECT DISTINCT url_default, name
				FROM catalog c
				WHERE c.parent = 0
				AND is_visible LIKE 'Yes' ";
		$pinn_cats = $pinn_db->get_results($querystr, OBJECT);

		foreach ($pinn_cats as $pinn_cat) {
			echo "<li><a href='/store/" . $pinn_cat->url_default . "' title='". $pinn_cat->name . "'>" . $pinn_cat->name . "</a>" . "</li>";
		}

Solution - 2

You can use the plugin WP Custom Widget to add PHP code in your sidebar. http://wordpress.org/extend/plugins/wp-custom-widget/

Solution - 3

Solution - 4

Use "bluesome.net/data/2005/08/exec-php.zip" and add your PHP code to post/pages/sidebar. Eg.

<?php
include('/path/to/database/connection.php');
?>

Solution - 5

I believe you might be asking for more detailed advice, some specific query code? - this depends on the stucture of the database you want to pull data from and some other circumstances. I guess this task might require more budget, just in case you might contact me so I can help you choose the proper solution: http://www.wpquestions.com/user/contact/id/530

Solution - 6

idem, http://wpquestions.com/user/profile/id/833