I try and get some help at the highslide forum, but most of the time they refer back to here.
But I understand that you don't know how to do it
Last year i tried to implement highslide in my html page with pictures from php. But i could not get it to work. Same as you it just shows letters (xxxx.jpg) and not the picture. In html, highslide needs pictures and thumb with extension.(xxxxx.jpg)
I also use a mod that extract text from my forum to my html webpage.Topic Extraction (news, latest topics etc) - 0.2.3. And I have also looked for a Mod that can extract uploaded pictures from phpbb.This would require the mod to make a thumb, and send the uploaded jpg and thumb to a folder before phpbb renames the .jpg to letters/numbers..or you will have to take alot off phpbb stuff to your html page, and rename your html to .php
So with lack of skills i will wait for MOD, or live with what i do now. That is manually to download from phpbb and move pictures to a folder, and implement in html code.I use a slideshow script. This also prevent a MOD from screwing up aspect ratio...also if lets say 50 pictures by 20 people is uploaded to phpbb the viewer wont see the first uploaded picture that much.