...ti ringrazio, ma sono debole in VB, ho riadattato parti trovate in rete.....
ti allego tutto il codice:

Option Compare Database
Option Explicit

Const PATH = "I:\dati\Digi\"

Private Const SW_SHOWNORMAL As Long = 1

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" ( _
ByVal hwnd As Long, _
ByVal lpOperation As String, _
ByVal lpFile As String, _
ByVal lpParameters As String, _
ByVal lpDirectory As String, _
ByVal nShowCmd As Long) As Long

Private Sub AprireMappa(ByVal strPath As String)
Call ShellExecute(Me.hwnd, "Open", strPath, vbNullString, vbNullString, SW_SHOWNORMAL)
End Sub


Private Sub btnOpen_Click()
Call AprireMappa(PATH & Me.codice.Value)
End Sub

Private Sub Comando90_Click()
On Error GoTo Err_Comando90_Click


Screen.PreviousControl.SetFocus
DoCmd.DoMenuItem acFormBar, acEditMenu, 10, , acMenuVer70

Exit_Comando90_Click:
Exit Sub

Err_Comando90_Click:
MsgBox Err.Description
Resume Exit_Comando90_Click

End Sub
Private Sub Comando93_Click()
On Error GoTo Err_Comando93_Click


Screen.PreviousControl.SetFocus
DoCmd.DoMenuItem acFormBar, acEditMenu, 10, , acMenuVer70

Exit_Comando93_Click:
Exit Sub

Err_Comando93_Click:
MsgBox Err.Description
Resume Exit_Comando93_Click

End Sub





...in problema è far diventare relativo il I:
in Const PATH = "I:\dati\Digi\"


GRAZIE MILLE