Multisite setup - want to redirect by IP/Country

I've successfully set-up a multi-site installation using symlinks that point to subdirectories, so that I have two sites - www.site.com/uk and www.site.com/ie that run off the one Drupal installation. However, this poses a problem when I try and redirect users based on their IP because the sites use the main index.php in www.site.com. Ideally I want UK users to be redirected to www.site.com/uk, and the rest of the world to be redirected to www.site.com/ie when going to the URL www.site.com.

First I tried using the ip2nation.com database with some redirect code, then I installed the GeoIP Apache module and tried using a .htaccess rewrite, but they both cause a redirect loop. This is because index.php is redirecting to /uk which is linked back to index.php, and so on!

I'm not sure where to start with the Drupal based modules, I have installed both IP to Country and IP to Locale, however ip2locale redirects to a language domain rather than to a specific page. It seems as though if I add any code to the index.php, it just creates one big redirect loop.

Any help on this would be greatly appreciated!