ActiveX Controls have been deprecated by Microsoft in the latest versions of the Windows operating system in favor of the DotNet framework and its controls.
While MAXScript still supports ActiveX controls, these have to be installed and registered on the system to be accessible to MAXScript.
As a replacement of ActiveX controls, MAXScript supports DotNet controls in 3ds Max 9 and higher.
To see whether an ActiveX property is an array, you can check for a hidden "_newEnum" property.
For example, . listItems in the ListView control, returns IListItems. This can be looped through and also indexed.