menu customization

[abayomi]

I am a newbie and i need help .
I appreciate the simplicity of get simple and i have also find the navigation plugins very good but i have been trying to use this template tag in customizing a menu to no avail.

Code:

<?php menu_data(); ?>, <?php menu_data('page-slug'); ?>

How do i use this in customizing the following codes cos i do not want to use the GS default get_navigation() function

Code:

<li><a href="<?php get_theme_url(); ?>/contact.html"><span class="meta">Get in touch</span><br />Contact Us</a></li>
            <li><a href="<?php get_theme_url(); ?>/blog.html"><span class="meta">Latest news</span><br />Blog</a></li>
            <li><a href="<?php get_theme_url(); ?>/portfolio.html"><span class="meta">Our latest work</span><br />Portfolio</a></li>

As you can see above,the page to be displayed per menu is not a get simple page and this is because i do not know how to use the menu function to determine the page to be displayed per menu.

pls help