diff -up extlink.js.orig extlink.js
--- extlink.js.orig	2008-10-15 11:44:57.000000000 -0500
+++ extlink.js	2008-10-15 11:45:43.000000000 -0500
@@ -29,7 +29,10 @@ if (Drupal.jsEnabled) {
     $("a").each(function(el) {
       try {
         var url = this.href.toLowerCase();
-        if (url.indexOf('http') == 0 && !url.match(internal_link)) {
+        var path_root = url.replace(/([a-z]+?):\/\/([^\/]+?)\/([^\/]+?)\/.*$/,'$3') ;
+        if ((url.indexOf('http') == 0) &&
+            ( (!url.match(internal_link)) || (path_root == 'extlink') )
+	    ) {
           external_links.push(this);
         }
         else if (url.indexOf('mailto:') == 0) {