phpbb3 preview image mod

Hi I own a porn forum based on phpbb3 forum software. Users post preview images of the videos and download links. It's annoying for users to keep clicking on topics to view what the thumbnail is. So when a user makes a post I would like it to take the first image in the post between the [img][/img] bbcode tags and add them as a preview image on the main forum page. For an example of what I mean please see this section [login to view URL] (egnore the site, its kinda strange lol). No attachments can be made so all images will be external. If no image is contained in the post then display nothing. Images obviously need to be scaled down to thumbnail size, the same as in that link. The image would be a hyperlink to the main topic. I use phpbb3seo on my sites, so the links need to follow the seo structure. I need instructions on how to implement the script as well so I can apply this to my other forums. All rights to me as well Simple script, lowest bid will win