Encryption at the database field level

Hello Everyone

I need a solution for the following problem ASAP

Configuration
SQL 2000 ENT Edition
Client - Server Application Designed in VB

I have one filed in one of my tables in a database E.g Credit Card Number. I need this fields to be Encrypted so that no body can see and mis use that information. One option is to change the application and incorporate the encryption logic into the application. Does SQL 2000 Provides some kind of Encryption at a field level? or can i manage this thing at the database level? I desperatelly want to do it at the database level.Refer to this MSDN link (http://msdn.microsoft.com/library/en-us/dnnetsec/html/SecNetHT19.asp) about using SSL communication.

Also on SQL Server level you can use MULTI-PROTOCOL netlib with ENCRYPTION option for the security, refer to books online for more information.