Help me call data out of MySQL with PHP please!!! vBulletin database

I need help. I have no idea what to do so if someoen can look into this and provide me with the codes I need it would be great!

I run vBulletin forum so the data I want is in my vB database. I am using a plugin, the iTrader plugin, I'm sure many of you are familiar with it.

Anyway with PHP I want to connect to this database and call info from this plugin specifically. I want a list of users with the most feedback (highest iTrader rating, which is a number) in descending order. I want it to list the username and next to it its iTrader rating as that's how feedback is displayed and collected in the database. I don't know how or what tables they are if someone has vB and can help me do that that would be great.

I want the list to look like this:

Bubba_Boom (100)
Flower Power (58)
OmegaFly (13)

So as you can see the list is in descending order according to iTrader rating, which should be put in parenthesis next to their username.

Because of the number of users I have with feedback, I'd like the following features:
- I want this to only display users in descending order with a MINIMUM iTrader rating of 20 (no maximum, but I should be able to specify this easily if I need to alter this minimum)
- I want a max of only 25 users to show so pages will be created to show more users if necessary via PHP

And alas, here is an example of what the feedback score system looks like in case you don't know:
eGaming Supply MMORPG Marketplace - iTrader - Monarch

The itrader rating is part of the plugin as it tracks the number of feedback you get (I think it tracks the number of positive particularly).

Anyway, you can see the link I gave you it's labeled on my site as feedback score.

If anyone can look into vBulletin and this plugin iTrader is what it's called, please help.