Exchange 2013 S/MIME with Server 2008 R2

So I am trying to configure S/MIME on my 2013 Exchange server, but the process in which I need to export the rootca is vague and only applies to Server 2012/Windows 8 because of the export-certificate command.  

http://technet.microsoft.com/en-us/library/hh848628.aspx

My domain consists of a single DC/CA and member server that hosts Exchange.  Both servers are on Server 2008 R2, and I have installed PowerShell v4.0 on my DC to try an export the certificate but it continues to fail with:

export-certificate : The term 'export-certificate' is not recognized as the name of a cmdlet, function, script file,
or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and
try again.

The examples given to set up the export are equally vague:

PS C:\>$cert= (Get-ChildItem -Path cert:\CurrentUser\My\EEDEF61D4FF6EDBAAD538BB08CCAADDC3EE28FF) <--What path is this referencing??
If anybody has experience doing this I would greatly appreciate some guidance.
Mike