Reading the LIST of Lookup Values for Enterprise Custom Field using VBA (2010)

Hello everybody,

My goal is to read from VBA the _list_ of allowed values that a given Enterprise Custom Field may have (MS Proj Pro 2010).

I'm making a UserForm that simplifies user input.

I can read/write the C.E.F. successfuly with 

    ActiveProject.ProjectSummaryTask.GetField(FieldID:=FieldNameToFieldConstant(MY_FIELD_NAME)

    ActiveProject.ProjectSummaryTask.SetField(FieldID:=FieldNameToFieldConstant(MY_FIELD_NAME), Value:="VALUE")

However I need to read WHICH VALUES are valid for a given EF so that I can build a combobox.

I've researched this topic extensively and I'm almost starting to believe that VBA cannot do it in 2010.

Can anyone help me prove me wrong on this?

Thanks (or: please :-)

Pedro