Refining objects returned from Get-IshFolderContent | Get-IshDocumentObjData

Hi, 

I am using a series of cmdlets in my ISHRemote call

Get-IshFolder -FolderPath "path to topics in tridion" | Get-IshFolderContent | Get-IshDocumentObjData -FolderPath "local path to download to

This returns every combination of logical, version, and language layers for the Tridion objects in the specified folder.

How can I refine my call to only return those where language layer is en-US?

Any advice appreciated,

Regards,

Ann