It would have been a good thing to put the urls inside code tags, so they don't get linked and shortened.
Code:
http://www.foro3d.com/post/722216-Critica-Americana-Planet-51
Code:
http://www.foro3d.com/threads/81976-Critica-Americana-Planet-51?p=722216&viewfull=1#post722216
If a redirect via htaccess is what you're looking for, that's not possible since the threadid (81976) is not present in the originating URL.