Option Explicit
Public colDocuments As New Collection
 
Sub Neu() ' neue Instanz erzeugen
Static x
Dim y
Dim f As New mdiDocument
     Static intDocumentNumber As Integer
intDocumentNumber = intDocumentNumber + 1
y = "Nr. " & intDocumentNumber
f.Caption = "Dokument Nr. " & intDocumentNumber
   ' Objektverweis zur Auflistung hinzufügen.
colDocuments.Add Item:=f, Key:=CStr(y)
f.Show
End Sub
 
Private Sub Command3_Click() ' Aufruf von Instanz Nr. x
Dim Abruf As Form
Dim x As Integer
x = InputBox("welches Fenster?")
Set Abruf = MDIForm1.colDocuments.Item(x)
Abruf.ZOrder 0
End Sub