You must load the exchange modules in your normal powershell session.
The required ones can you see when you use the follwing command:
Get-PSSnapin -registered
The output looks similar:
Microsoft.Exchange.Management.PowerShell.E2010
Microsoft.Exchange.Management.PowerShell.Setup
Microsoft.Exchange.Management.Powershell.Support
You can load them with the add-pssnapin command.
Regards
Jörg