Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Excel.Range, Cancel As Boolean)
Dim testo As String
Dim nomefile As String
Dim path As String

On Error Resume Next

If Target.Column = 5 Then

    path = "C:UsersAlex"
    testo = path & Cells(Target.Row, 5)
    nomefile = Dir(Left(testo, Len(testo)) & "*.pdf")

    If nomefile = "" Then
        MsgBox "File non trovato", vbCritical, "ATTENZIONE"
        Exit Sub
    End If

    Do
        Shell "C:Program Files (x86)AdobeReader 11.0ReaderAcroRd32.exe " & path & nomefile, vbMaximizedFocus
        nomefile = Dir
    Loop While nomefile <> ""
End If