If you want to backup UCC SSL with private key, use the following command:
Export-ExchangeCertificate -Thumbprint -BinaryEncoded:$true -Path c:\certificates\export.pfx -Password:(Get-Credential).password
Command to import SSL:
Import-ExchangeCertificate -Path c:\certificates\export.pfx -Password:(Get-Credential).password
To get Thumbprint SSL of installed certificate, open Exchange Management Shell (Start -> Programs -> MS Exchange 2007 -> Exchange Management Shell) any type the command:
Get-ExchangeCertificate
