If I have a Workbook with code opened, and an external application creates
and open a new workbook this second workbook is opened in a new Excel
Enviroment and I coudn't access to it form the first one.

I have to windows opened, but the code only returns one.

Public Function funfinestres()
Dim wdw As Window
For Each wdw In Application.Windows
MsgBox wdw.Caption
Next
End Function