Making my own hack, where's database entry?

[youradultworld]

If I was to try and add an extra data field to my vbulletin such as a zipcode, I know that I can add this in the admin section, but if I want to perform a function on the data stored for that particular user for the zipcode or whatever, where do I find this newly entered data in the database?

I want to be able to have users enter their zipcode and then when someone does a search I can specify within how many miles of their zipcode and stuff. Just please tell me where to find this data in the database so that I can manipulate it.

Thanks,

Chris