DLL call

I'm having problem calling dialog based DLL made in VB5 and calling
from AutoCAD 2000i (OS: windows 2000). Here is the project.
It is very simple and for testing purpose only.
I've tried to cover VB Variant (Array) and Collection types
to see what type is actually converted <safearray...> in VB. I've tried to
use
vlax-vbVariant and vlax-vbString types to convert AutoLisp 'LIST type for
the same porpuse too.
Here is the project

vb PROJECT called "ListBox"

FORM called "frmListBox". With a single object on it
LISTBOX called "List1"
CLASS called "clsListBoxArr". With a single public function
called "ListBoxArr" as

Public Function ListBoxArr(arrItems As Variant)
Dim frm As New frmListBox
Dim Count As Integer

With frm.List1
For Count = 0 To UBound(arrItems)
.AddItem arrItems(Count)
Next
.ListIndex = 0
End With
End Function


CLASS called "clsListBoxColl". With a single public function
called "ListBoxColl" as

Public Function ListBoxColl(collItems As Collection)
Dim frm As New frmListBox
Dim Count As Integer

With frm.List1
For Count = 1 To collItems.Count
.AddItem collItems(Count)
Next
.ListIndex = 0
End With
End Function

Now from AutoCAD I'm calling both objects to see with one will work.

Call 1: As array variant

(setq AA (vlax-create-object "ListBox.clsListBoxArr"))
(setq ref (list "ABC" "DEF" "GHI")
vL (vlax-make-safearray vlax-vbVariant (cons 0 (length ref))) ;;; This
is also a test to see which way
sL (vlax-make-safearray vlax-vbString (cons 0 (length ref))) ;;;
(vbVariant or vbString) will work
i 0)
(while (<= i (length ref))
(setq xx (vlax-make-variant (nth i ref)))
(vlax-safearray-put-element vL i xx)
(vlax-safearray-put-element sL i xx)
(setq i (1+ i)))
(vlax-invoke AA 'ListBoxArr vL) ; error: ListBox: Type mismatch
(vlax-invoke AA 'ListBoxArr sL) ; error: ListBox: Type mismatch

Call 2: As collection

(setq BB (vlax-create-object "ListBox.clsListBoxColl"))
(setq ref (list "ABC" "DEF" "GHI")
vL (vlax-make-safearray vlax-vbVariant (cons 0 (length ref))) ;;; This
is also a test to see which way
sL (vlax-make-safearray vlax-vbString (cons 0 (length ref))) ;;;
(vbVariant or vbString) will work
i 0)
(while (<= i (length ref))
(setq xx (vlax-make-variant (nth i ref)))
(vlax-safearray-put-element vL i xx)
(vlax-safearray-put-element sL i xx)
(setq i (1+ i)))
(vlax-invoke BB 'ListBoxColl vL) ; error: argument type mismatch:
#<safearray...>
(vlax-invoke BB 'ListBoxColl sL) ; error: argument type mismatch:
#<safearray...>

but there is no success at all with maximum options I tried to cover.
Where I'm doing wrong? Can someone help me here?

Thanks