I believe it fails to work because of the '2'. There's a ticket raised already for expanding the allowable URL's in CONF-28103 so best to put a watch on that Joe.

I also don't like that this is called a "new feature request" since it works fine in version 3.1. Our production wiki runs on Confluence v3.1 and we were trying to upgrade to 4.3.7, but this is a major road block for us.

Sorry, but I gave Andrew a false affirmative that the Espresso he linked here was correct. It is not. We use an internally developed cocoa-based app called Espresso. It is a ticketing system that routes to our internal Information Systems & Technology team. There isn't much (if any at all) on the open web about the app, but I could possibly get you whatever you need to make it work. Seems like it should be a simple fix to allow "exp2://" hyperlinks just like you do for "rdar://" hyperlinks which open tickets in our other internally developed cocoa-based app called Radar. Thanks.