[Plugin: NextGEN Gallery] Nextgen Gallery shadowbox.js setup

Hi! I have a little problem:
I’m using NGGallery with a custom effect (shadowbox).
It works quite well, but the js has an option that I’m trying to use with NGG: The Image title in the upper side of the image window.
I started trying to modify the code in the option page
rel="shadowbox[%GALLERY_NAME%]" title="%IMAGE_NAME%"
But the tag %IMAGE_NAME% is not supported.
However, I saw that this code duplicates the link title=””, and it’s not good.
So I need to modify the plugin code to show the image title in the link title.
I mean:

<div class="ngg-gallery-thumbnail"  >
	<a href="http://www.something.com/wp-content/gallery/galleryname/image.jpg" title="I NEED TO PUT THE IMAGE TITLE / ALT HERE" rel="shadowbox[galleryname]" ><img title="THE SAME THAT IS HERE" alt="OR HERE" src="http://www.something.com/wp-content/gallery/galleryname/thumbs/thumbs_image.jpg" style="width:100px; height:75px;" /></a>
</div>

But I can’t find where this code is!
Can Someone help me?
What nggfile.php i need to look for?

Thank you very much.

Francesco