[Plugin: NextGEN Gallery] singlepic full image URL

I’ve been trying to figure this out for a while now with no success. Here’s the problem, my page has a large singlepic at the top and a gallery of thumbnails below. I’m trying to get the singlepic to act like it’s a member of the gallery. The last hurdle is I need to access the singlepic’s full image url somehow. I found this comment in the code:

Function to show a single picture:
     *     [singlepic id="10" float="none|left|right" width="" height="" mode="none|watermark|web20" link="url" "template="filename" /]
     * where
     *  - link is optional and could link to a other url instead the full image

All I need to make this work is a way to get that default full image url. The code in my php file looks like this:

<?php echo do_shortcode("[singlepic id= $custom_field_featuredImage w=780 h= float=]"); ?>

I need to add link="something" to that. Anyone? I’m dying over here! Thanks.

http://ww.wp.xz.cn/extend/plugins/nextgen-gallery/