Export EFS Certificate W2K Pro>XP Pro

Hi,
I have one pc running Windows 2000 Pro and I want to export it the certificate to a Windows XP Pro machine. I have put a folder in the shared documents folder on the Windows XP Pro machine and encrypted it. I saved all the files in the folder after it was encrypted. I want to be able to access the folder from the Windows 2000 Pro computer. They are on a P2P network and can access the shared documents folder and view all other info in the folder. how do I export the certificate to do this. Or,is there an easier way to give access to only one user on a five machine network. 4 pc’s run XP Pro and one runs 2000 pro.