How to display usernames and custom profile fields in external pages?

[Nolandis]

Hi! This is my fist post (even though I'm not newly registered)... Today and part of yesterday I've been browsing for hours looking if my problem has been posted here before, but without luck.

First of all, let me be a bit more clear. I don't want to display my username while I'm logged in (what $vbulletin->userinfo['username'] does).

What I'm looking for is a way to show existing usernames registered in my forum in an external php page, regardless if I'm logged in or not. I'm not sure how to achieve that, but I don't think it should be difficult.

Basically what I want to do is a list of all the users that have a certain profile field filled, and those who leave it blank should not be added.

I'll appreciate any help!

And Happy Holidays!