Encryption Decryption Help Needed

I have a situation where users will be entering their credit card number then the number will be stored in the MicroSoft SQLdatabase. I already have SSL in place but what I would like to do is to encrypt the number in the database to help my CIO sleep at night. We have constructed a report to get retrieve the stored information that is locked down hard using IP address validation and several other IIS security methods...but I will need to have the credit card number decrypted in this report. Can anyone point me to a method to encrypt the Credit card number on insertion into the database, and then decryption when reporting? I have MCrypt installed and functioning correctly on my server, I just can't find any simple tutorials on how to do this. Thanks, Ron