Private Sub Workbook_Open()
Dim succes As Boolean
Dim addinPath, addinName, addinFullName, defaultPath As String

    addinPath = IIf(Not ActiveWorkbook Is Nothing, ActiveWorkbook.Path, _
                IIf(Not ActiveWindow.Parent Is Nothing, ActiveWindow.Parent.Path, _
                    ThisWorkbook.Path))

    addinName = "gmafffff.excel.udf"
    #If Win64 Then
        Debug.Print ("x64")
        addinName = addinName & "_x64.xll"
    #Else
        Debug.Print ("x32")
        addinName = addinName & "_x32.xll"
    #End If
    addinFullName = addinPath & "\" & addinName

    defaultPath = Application.DefaultFilePath
    Application.DefaultFilePath = addinPath

    For Each надстр In Application.AddIns2
        If надстр.Name = addinName Then
            Exit Sub
        End If
    Next

    Debug.Print ("Load addin")
    succes = Application.RegisterXLL(addinFullName)

    If succes Then
        Debug.Print ("addin " & addinName & " успешно загружен")
    Else
        Debug.Print ("addin " & addinName & " не загружен")
    End If

    Application.DefaultFilePath = defaultPath
End Sub