XF 1.4 How to type a URL based on POST number, not thread number?

I'm having a simple contest to celebrate our forum's ten year anniversary. I want to give away prizes based on a random POST number, not thread number.

XF does a great job of correcting a URL based on changing the thread number (without needing to correctly type the whole URL), but not by post number.

For example, you can paste "http://www.chiptalk.net/forum/threads/new-years-pr0n-mixed-lv-cashgame-set.89692" and then change the 89692 to 89691 and it'll translate to the correct full URL of that new thread.


Paste "http://www.chiptalk.net/forum/threads/new-years-pr0n-mixed-lv-cashgame-set.89692/#post-1295513" and try to change the post number from 1295513 to something else and it doesn't work the same.

Stated another simple way: "How can I look at any random post to see who the poster is, from between two specific post numbers?"

Thanks in advance!