$Searcher = New-Object -TypeName System.DirectoryServices.DirectorySearcher -ErrorAction Stop
$DomainRoot = ([ADSISearcher]"").SearchRoot.Path
$Searcher.SearchRoot = $DomainRoot
$Searcher.PageSize = 1000
$Searcher.Filter = "(&(objectCategory=user)(memberOf=CN=FS-Exchange-M,OU=Groups,OU=mydomain,DC=mydomain,DC=loc))"
$Ask = $Searcher.FindAll()
$Ask