Go to URL which is in the attachments’s description

Dear All,
This is my webpage: LINK.
Could you please help me? I have a Portfolio page which contain the project’s attachment thumbnails.
You can see here!

What I would like to: When I click to the thumbnails, go to URL (target: new window) which is in the attachments’s description. So, NOT to the project page…

Here is the code for this template which I have:

<?php get_header(); ?>

   <!-- start content wrapper -->
	<div class="container">
		<div class="page-title">
			<h1><?php the_title(); ?></h1>
		</div>
		<div class="divider mbottom10 clear"></div>
		<!-- start portfolio filter -->
		<div class="filter" id="filter">
			<ul>
				<li>
					<a title="Link title" class="active" href="#" data-category="all">All</a>
				</li>
				 <?php
					$categories = get_categories('type=portfolio&taxonomy=portfolio-type');
					foreach ($categories as $category) {
				?>		

					<li class="<?php echo $category->slug ?>" >
						<a href="" data-category="<?php echo $category->slug ?>"><?php echo $category->name ?></a>
					</li>

				<?php }	?>
			</ul>
		</div>
		<!-- end portfolio filter -->

		<div class="divider clear"></div>				

		<!-- start portfolio items -->
		<div class="portfolio-wrapper">
				<ul class="isotope-container">

					<?php $args = array(
						'post_type' => 'portfolio',
						'posts_per_page' => -1
					);
					$query = new WP_Query( $args );

					while ( $query->have_posts() ) : $query->the_post();  ?>

					<?php
						$terms =  get_the_terms( $post->ID, 'portfolio-type' );
						$term_list = '';
						$image_url = wp_get_attachment_image_src(get_post_thumbnail_id($post->ID), 'featured-image-thumb');
						$featured_image = quick_resize('248','165', $image_url[0]);
						if( is_array($terms) ) {
							foreach( $terms as $term ) {
								$term_list .= $term->slug;
								$term_list .= ' ';
							}
						}
					?>
					<?php $mediaType = get_post_meta($post->ID, '_project_type_value', true);

					switch( $mediaType ) {
					case "Image":
					case "Slideshow": ?>							

					<!-- start work -->
					<li id="<?php echo the_ID()?>" <?php post_class("$term_list isotope-item all"); ?> >
						<?php if(has_post_thumbnail()): ?>
						<div class="portfolio-thumb hasheight">
							<a class="linkto" href="<?php the_permalink(); ?>" title="<?php printf(__('Permanent link to %s', 'photolio'), get_the_title()); ?>">
								<img src="<?php echo $featured_image; ?>" title="<?php the_title(); ?>" alt="<?php the_title(); ?>" />
								<span class="over-more"><?php _e('View project','photolio') ?></span>
								<span class="over-more-title"><?php the_title(); ?></span>
							</a>
						</div>
						<?php endif; ?>
					</li>

					<?php break; 

					} endwhile; ?>
					<!-- end work -->
				</ul>
		</div>
		<!-- end latest work -->
	</div>
	<!-- end content wrapper -->

<?php get_footer(); ?>

I would really appreciate any help! 🙂

Thank you!
Regards,
toserandras