Freeing Excel after using Interop

I have read many posts looking for my answer, but they are all like this: Reading excel files in vb.net leaves the excel process stuck

My problem is that I am not logging out of the application ...

The idea is this:

If the user has Excel Open, if he has a file that I am interested in opening ... get an instance of Excel and do whatever I want to do ...

But I don't close his File after I am done ... I want him to keep working on this, the problem is when he closes Excel ... The process keeps running ... and running ... and running after the user closes Excel with the X ...

this is how i try to do it

This part is used to find out if Excel is open, and in the "I" field I check the file name that interests me.

    Try
        oApp = GetObject(, "Excel.Application")
        libroAbierto = True
        For Each libro As Microsoft.Office.Interop.Excel.Workbook In oApp.Workbooks
            If libro.Name = EquipoASeccionIdSeccion.Text & ".xlsm" Then
                Exit Try
            End If
        Next
        libroAbierto = False
    Catch ex As Exception
        oApp = New Microsoft.Office.Interop.Excel.Application
    End Try

      

        
        
        
      

    

here would be my code ... if it didn't open Excel, I create a new instance, open the file and everything else.

My code ends with this:

If Not libroAbierto Then
        libroSeccion.Close(SaveChanges:=True)
        oApp.Quit()
    Else
        oApp.UserControl = True
        libroSeccion.Save()
    End If    
    System.Runtime.InteropServices.Marshal.FinalReleaseComObject(libroOriginal)
    System.Runtime.InteropServices.Marshal.FinalReleaseComObject(libroSeccion)
    System.Runtime.InteropServices.Marshal.FinalReleaseComObject(origen)
    System.Runtime.InteropServices.Marshal.FinalReleaseComObject(copiada)
    System.Runtime.InteropServices.Marshal.FinalReleaseComObject(oApp)
    libroOriginal = Nothing
    libroSeccion = Nothing
    oApp = Nothing
    origen = Nothing
    copiada = Nothing
    nuevosGuardados = True

      

        
        
        
      

    

So you can see that if I open the file, I call oApp.Quit () and everything else, and the Excel process ends after a few seconds (maybe 5 aprox.)

BUT, if I mean that the user has to keep the file open (without calling Quit ()), the Excel process continues to run after the user closes Excel with the X button.

Is there a way to do what I am trying to do? Manage the open excel instance and freeing everything so that when the user closes it with the X button, the Excel process usually dies

Thanks!!!