I've never had to do what you need to, but a thought came to mind.  Why not
test for the existing of the network drive.  Simply use the Dir() function.  
Try somthing like

If Len(Dir("z:"))>0 Then
   'Connection to server established

Else
   'No connection established

End If

assuming z: is your network drive that you need to check your connection to.

That's why you have an error handler in your startup code when you
check your links:
on error goto ErrHandler
'Test if you can refresh a link
currentdb.tabledefs("SomeBETable").RefreshLink
...
exit function
ErrHandler:
Msgbox "Yo! No back end found here: " &
currentdb.tabledefs("SomeBETable").Connect
end function

Hi,

Instead of linking with an autoexec macro I use a form to authentic
against the server and then link the tables. That way the server must be
there before linking begins.

Create a table in the FE called ODBCTables one column with the names of
the tables you wish to link.

Create your login form and under a command button  call LinkTables
Note that in the following code; server, dbase, user, pass are all input
fields on the login form. Also make sure you specify the ODBC driver. In
the code below is a MySQL driver you will need to replace it with the
appropriate driver for the server you are connecting to.

Public Sub LinkTables()
On Error GoTo ErrTrp

Dim db As Database, rs As Recordset, tdf As TableDef
Dim dbODBC As Database, strConnect As String
Dim strMsg As String
Dim SrvrNm As String
Dim DbNm As String
Dim UsrNm As String
Dim Pswd As String
ServerName = Me.server
DatabaseName = Me.dbase
UserName = Me.user
Password = Me.pass

Call DelODBC

strConnect = "DRIVER={MySQL ODBC 3.51 Driver};DATABASE=" & _
                        DbNm & ";SERVER=" & SrvrNm & _
                        ";Uid=" & UsrNm & _
                        ";Pwd=" & Pswd & ";"
Set db = CurrentDb
Set rs = db.OpenRecordset("ODBCTables")
Set dbODBC = OpenDatabase("", False, False, strConnect)

Do While Not rs.EOF
  Set tdf = db.CreateTableDef(rs![TableName], dbAttachSavePWD)
  tdf.Connect = dbODBC.Connect
  tdf.SourceTableName = dbODBC.TableDefs(rs![TableName]).Name
  db.TableDefs.Append tdf
  rs.MoveNext
Loop

rs.Close
Set rs = Nothing
Set dbODBC = Nothing
Set db = Nothing

ExitTrp:

    Exit Sub

ErrTrp:
If Err.Number = 94 Then
    strMsg = "User name or Password is blank. Re-enter details or
contact the system administrator."
    If MsgBox(strMsg, vbRetryCancel, "Oh Bother!! Locked out again") =
vbCancel Then
    DoCmd.Quit
    End If
    GoTo ExitTrp

End If

End Sub

Public Sub DelODBC()
On Error GoTo ErrTrp

    Dim db As Database, tdf As TableDef, i As Integer
    Set db = CurrentDb
    For i = db.TableDefs.Count - 1 To 0 Step -1
      Set tdf = db.TableDefs(i)
      If (tdf.Attributes And dbAttachedODBC) Then
        dbs.TableDefs.Delete (tdf.Name)
      End If
    Next i

    db.Close
    Set db = Nothing

ExitTrp:
    Exit Sub

ErrTrp:
Resume ExitTrp

End Sub

HTH,
Regards,
Nick.