I'm currently working on a website that mostly operates outside of phpBB but is integrated with the phpbb login system so that visitors can use the forums. Due to this, I have a number of custom profile fields set up that I need to be able to display and update outside of phpBB with some sort of code.
I already found this topic on how to display custom profile fields: http://www.phpbb.com/community/viewtopic.php?f=71&t=730885
I'm using the method explained in the 5th post of that topic and it works perfectly for displaying CPF values. It seems to me that there must also be some kind of built-in TEMPLATE/method in phpBB for updating the data in those fields. That is, to change the value of those fields like with the MySQL UPDATE query.