Doesn't seem to like that syntax:

For Each $Element In $user.msExchADCGlobalNames
If Not $Element =""
$Element.PutEx (1,"msExchADCGlobalNames","")
? $User.Name + " ADCG cleared."
$user.Setinfo/
endif
Next

Script error : unknown command !
$Element.PutEx(1,"msExchADCGlobalNames","")