Unfortunately, it may not be that simple. Jim has 4,089 posts. Using this site to search posts by G3Kurz turns up 71 results:
If you search Google for G3Kurz, every thread that mentions him will turn up, not just the ones he posted in. The best Google search I can think of is to search HKPro.com for mentions of his location. That search retrieves ~1,170 results:
That's a start if Jim posted in ~1,170 threads. Although I'm not sure if that is close to the actual number of threads, and I'm not sure if we would be missing anything important by going that route. The best option would be to pull all of the posts with a MySQL query on a backup of the site's database into something like an HTML or CSV file. We would need assistance from an administrator to do that.
I neve thought this project would ever be fruitful without the direct support of the site admin.