[URGENT] Unique User Profile Field

[Lind101]

Firstly, hello to everyone of VBulletin.org.

Now to the problem. I have a board which i have linked up to the Login Server of an Online Game that i have created. To login to this game you are required to enter your GameID (A private User Profile Field i have added to the registration form and is mandatory upon forum registration) and your forum password. All works fine, however i suddenly realised that this new field i have added is not unique, which means two people may enter the same GameID which obviously would in turn cause havoc for the Login Server as it is unable to determine between accounts with the same GameID.

The reason i have decided to do it this way? Security. If i did it solely off the forum username, potential hackers would already have half of the login details and would only need the password to hack the account. This way the extra ID is kept secret and only know to the creator of the forum account.

So the question is, upon registration, is there anyway that i can get VB to check that the entered User Profile Field (GameID) is unique? Much like it does with username and email?

If not does anyone know how any hacks/mods that might allow me to add and check such a field straight into the "user" table rather than "userfield"?

Thanks in advance.

Lind