Hi maperalia,

You can only have truly automatic updating if the Word document and the
file(s) it's linked to are kept in the same folder. If that applies in your
case, try the following code:

Option Explicit
Public SFileName As String

Sub AutoOpen()
' This routine runs whenever the document is opened. It mainly performs a
set of housekeeping functions.
' Most of the work is done by the UpdateFields and GetSourceFileName
routines.
Dim sBar As Boolean, oSection As Section, shp As Shape, oHeadFoot As
HeaderFooter
sBar = Application.DisplayStatusBar ' Store StatusBar visibility condition
Application.DisplayStatusBar = True ' Make StatusBar visible
Application.ScreenUpdating = False ' Minimise screen flicker
Selection.EndKey Unit:=wdStory
ActiveWindow.View.ShowFieldCodes = True
Call UpdateFields
' Set the saved status of the document to true, so that path update changes
via this macro are ignored.
' Since they'll be recreated the next time the document is opened, saving
such changes doesn't really matter.
' Then clean up and exit.
ActiveDocument.Saved = True
ActiveWindow.View.ShowFieldCodes = False
On Error Resume Next ' In case there's only one active pane
ActiveWindow.ActivePane.Close
If ActiveWindow.View.SplitSpecial = wdPaneNone Then
   ActiveWindow.ActivePane.View.Type = wdPrintView
Else
   ActiveWindow.View.Type = wdPrintView
End If
Application.DisplayStatusBar = sBar ' Restore StatusBar to original
visibility condition
Selection.HomeKey Unit:=wdStory
Application.ScreenUpdating = True
End Sub

Private Sub UpdateFields()
' This routine sets the new path for external field references, calls the
GetSourceFileName routine to get the
' link's filename, plus any bookmarks and switches from the original field
then merges these into a new field.
Dim wdRange As Range, FieldCount As Integer, FieldType As String, NewPath As
String, NewField As String
' Get the new path
NewPath = Replace$(ActiveDocument.Path, "\", "\\") & "\\"
' Go through the document, updating all external field links with the new
path.
For Each wdRange In ActiveDocument.StoryRanges
   If wdRange.Fields.Count > 0 Then
       For FieldCount = wdRange.Fields.Count To 1 Step -1
           wdRange.Fields(FieldCount).Select
           With wdRange.Fields(FieldCount)
               Select Case True
               Case .Type = wdFieldHyperlink
                   FieldType = "HYPERLINK"
               Case .Type = wdFieldIncludeText
                FieldType = "INCLUDETEXT"
               Case .Type = wdFieldIncludePicture
                   FieldType = "INCLUDEPICTURE"
               Case .Type = wdFieldLink
                   FieldType = "LINK"
               Case .Type = wdFieldRefDoc
                   FieldType = "RD"
               Case Else
                   FieldType = ""
               End Select
           End With
           If FieldType <> "" Then
               Call GetSourceFileName
               NewField = FieldType & " " & """" & NewPath & SFileName
               Application.StatusBar = "Updating " & SFileName ' Show
progress on status bar
               With Selection
                   .Delete
                   .Fields.Add Range:=Selection.Range, Type:=wdFieldEmpty,
Text:=NewField, PreserveFormatting:=False
               End With
           End If
       Next FieldCount
   End If
Next wdRange
Application.StatusBar = "Finished!"
End Sub

Private Sub GetSourceFileName()
' This routine gets the source file's name, plus any bookmarks and switches
from the original field.
Dim CharPos As Integer
SFileName = Selection
For CharPos = Len(SFileName) To 0 Step -1
   On Error Resume Next 'In case there's no path
   If Mid(SFileName, CharPos, 2) = "\\" Then
       SFileName = Mid(SFileName, CharPos + 2)
       Exit For
   End If
Next CharPos
'Delete any extra spaces on the right, but preserve leading & internal
spacing.
SFileName = RTrim(Replace$(SFileName, Chr(21), ""))
End Sub

Otherwise, your users must tell Word where to find the document's source
files, as per Doug's code or the utility I pointed you to. Doug's code
requires you to nominate both the fold and filename for each link. My
utility allows for the possibility that more than one folder might be
involved, but the users only have to select the folder, not the file and,
once a given path has been changed, all subsequent references to that path
are changed without further user intervention. Of course, if the user form
gives too many options, you could delete the one's you don't want/need.

Cheers