Help With shortcode

Hello can someone please help me i need to setup some shortcode here is the code that i what as shortcode.

” rel=”lightbox” title=”<?php echo c2c_get_custom(‘title’); ?>”><img src=”<?php echo c2c_get_custom(‘thumb’); ?>” width=”60″ height=”45″ alt=”df” />

Ive been looking at smashing magazines shortcode and come up with this.

function insert() {
return ‘” rel=”lightbox” title=”<?php echo c2c_get_custom(‘title’); ?>”><img src=”<?php echo c2c_get_custom(‘thumb’); ?>” width=”60″ height=”45″ alt=”df” />‘;
}

add_shortcode(‘image’, ‘insert’);

but i get errors im a newbie to php and would really appreciate some help. Or a push in the right direction.