get item index

is there a way to get item index?

Set item1 = ThisDrawing.ModelSpace.Item([index])

item1.XXXX = [index]

XXXX which property?

ObjectID,OwnerID is not index..

or is there a way to get item from ownerID?

Set item1 = ThisDrawing.ModelSpace.YYYY([OwnerID] or [ObjectID])

YYYY which object?

Why do you need the index?

You can convert to VLA-Object from ObjectID/Handle.

How can we do that?

Using an ObjectID

In LISP:

(vla-ObjectIDtoObject
 (vla-get-ActiveDocument
   (vlax-get-acad-object)
 )
 <ObjectID>
)

In VBA:

ThisDrawing.ObjectIdToObject(objectID)  

Or using a Handle:

In LISP:

(vla-HandletoObject
 (vla-get-ActiveDocument
   (vlax-get-acad-object)
 )
 <Handle>
)

In VBA:

ThisDrawing.HandleToObject(handle)