Unable to configure Outlook Everywhere

I have Exchange 2010, and am trying to configure Outlook Everywhere.   The IIS server has a wildcard certificate (*.domain.com).  

I found several references that to set this to work, I simply need to run:

Set-OutlookProvider EXPR -CertPrincipalName msstd:*.domain.com

When I run it - I get:

[PS] C:\Windows\system32>Set-OutlookProvider EXPR -CertPrincipalName msstd:*.domain.com
Active Directory operation failed on server.domain.com. This error is not retriable. Additional information: Insuff
icient access rights to perform the operation.
Active directory response: 00002098: SecErr: DSID-03150BB9, problem 4003 (INSUFF_ACCESS_RIGHTS), data 0
    + CategoryInfo          : NotSpecified: (0:Int32) [Set-OutlookProvider], ADOperationException
    + FullyQualifiedErrorId : 2022A968,Microsoft.Exchange.Management.SystemConfigurationTasks.SetOutlookProviderTask

I am running this from the shell on the exchange server and am in all of the security groups.  

Get-OutlookProvider  returns :

Name                          Server                        CertPrincipalName             TTL
----                          ------                        -----------------             ---
EXCH                                                                                     1
EXPR                                                                                     1
WEB                                                                                      1

Any Suggestions?