Outlook Add Multiple Attachments via file dialog box

Hello,

I'm trying to write a code which would add files to currently opened email via file dialog box. But I can't find any proper information about file dialog box in Outlook. Could someone help me with this?

Sub test()


Dim objOutApp As Object, objMail As Object
  Dim myItem As Outlook.MailItem
    Dim myAttachments As Outlook.Attachments
    Set myItem = Application.ActiveInspector.CurrentItem
    Set myAttachments = myItem.Attachments
    myAttachments.Add ("P:\Work\test.xlsx")
    myAttachments.Add           <-------- open file dialog box here to select multple files
End Sub