I'm look for a simple plug for CB that will allow my registration page to have an addition authentication field that will auto generate a series of numbers.

Example:

Username
Password
*series of numbers* (12548895)

This way the user or allowed visitor can login with the username and/or the password or these "series of auto generated numbers".

I can not find this kind of plugin/component anywhere...
Can this be developed rather quickly? ... Anyone

Any help would be greatly appreciated!!