Trying to create an LDAP-based Dynamic filter

Hi,

I've an old Dyn Group (from 2003) which was based off an LDAP query of:

(&(!cn=SystemMailbox{*})(&(&(&(& (mailnickname=*) (| (&(objectCategory=person)(objectClass=user)(!(homeMDB=*))(!(msExchHomeServerName=*)))(&(objectCategory=person)(objectClass=user)(|(homeMDB=*)(msExchHomeServerName=*)))(&(objectCategory=person)(objectClass=contact))(objectCategory=group)(objectCategory=publicFolder)(objectCategory=msExchDynamicDistributionList) )))(objectCategory=user)(physicalDeliveryOfficeName=Somewhere))))

In theory, that can be reduced in 2010 to a recipient filter something like:{ ((RecipientType -eq 'UserMailbox') –and (Office -eq 'Home')) }

But if I try creating the group I get:

IncludedRecipients: [PS] C:\Windows\system32>New-DynamicDistributionGroup -Name "All-Teleworkers" -RecipientFilter { ((RecipientType -eq 'UserMailbox') -and (Office -eq 'Home')) }
Invoke-Command : Cannot bind parameter 'RecipientFilter' to the target. Exception setting "RecipientFilter": """ is not
 a valid operator. For a list of supported operators see the command help.
" ((RecipientType -eq 'UserMailbox') -and (Office -eq 'Home')) " at position 37."
At C:\Users\me\AppData\Roaming\Microsoft\Exchange\RemotePowerShell\server.ubiquisys.local\server.ubi
quisys.local.psm1:25779 char:29
+             $scriptCmd = { & <<<<  $script:InvokeCommand `
    + CategoryInfo          : WriteError: (:) [New-DynamicDistributionGroup], ParameterBindingException
    + FullyQualifiedErrorId : ParameterBindingFailed,Microsoft.Exchange.Management.RecipientTasks.NewDynamicDistributi
   onGroup

How do I create a group, where the LDAP attribute (physicalDeliveryOfficeName=Somewhere)