W2K Encryption Recovery

I have a huge problem and hope someone can help:
One of our executives had encryption set on critical folders and his laptop crashed. We forunately had a backup of his data via BackupExec and had to format the HDD.

I have restored the data but cannot recover the encrypted files. I built a W2K Server with Active Directory etc and configured Certificate Services but still could not unencrypt the data as the Administrator.

Any help would be appreciated.