Conrad, You can do it this way. You must download AutoItObject UDF. Parent.au3: #include <Array.au3> #include "AutoItObject.au3" MsgBox( 0, "Parent", "This is parent" ) _AutoItObject_StartUp() ; Register object to transfer data Global $sDataTransferObject = "DataTransferObject" Global $oDataTransferClass, $oDataTransferObject, $hDataTransferObject $oDataTransferClass = _AutoItObject_Class() $oDataTransferClass.AddProperty( "ArrayDat