Adding Random Image Block to phpBB3.0.5

Can anyone tell me if there are any issues with adding a line like
<?php @readfile('http://www.xxxxxx.net/xxxxxgallery/gallery2/main.php?g2_view=imageblock.External&g2_blocks=randomImage&g2_show=title'); ?>
Within phpBB3.0.5?
What php file would you add this line in to link to an external image from a php gallery? I am interested in basically displaying a random image link from a php gallery on the main page of a phpBB forum.

I have posted this in the support form at phpBB but have not gotten any response yet so I was curious if anyone here has done this yet and would give any tips.

Thanks.

Gallery RULES!