Dynamic PNG Signature

[wichall]

I want to make a dynamic PNG signature that has info from different user's profile fields.

I was looking at this page on dynamic PNGs http://www.swish-db.com/tutorials/view.php/tid/383 but what i want is something more along the lines of this: http://www.rs3stats.co.uk/ in the way that the PNG changes depending on what user is put in the place of "<gamertag>" ( http://statsigs.rs3stats.co.uk/rs3/<gamertag> ).

Does anyone know how I can do this?