Hi

The only way I know to do this is to use a macro that inserts your watermark
and changes the text for each copy.

If you don't know what to do with the macro below, see
http://www.gmayor.com/installing_macro.htm

Option Explicit

Sub Print50Documents()
'Shauna Kelly for
'microsoft.public.word.numbering
'9 January 2005

Dim oShape As Word.Shape
Dim nCounter As Long
Dim sMyMessage As String
Dim nHowManyCopies As Long
Dim nLeft As Long
Dim nTop As Long
Dim bPrintOut As Boolean

'Change the following to suit your needs
sMyMessage = "Copy Number "
nLeft = 75
nTop = 450

'Change the following to say
'50 when you're confident
'it will work
nHowManyCopies = 2

'Change the following to True to
'actually print. Leave it at
'False to test.
bPrintOut = False

   ActiveWindow.ActivePane.View.SeekView = _
       wdSeekCurrentPageHeader
   With Selection
       Set oShape = .HeaderFooter.Shapes.AddTextEffect _
       (PresetTextEffect:=msoTextEffect2, _
       Text:=sMyMessage & Str(nCounter), _
       FontName:="Arial", _
       FontSize:=1, _
       FontBold:=False, _
       FontItalic:=False, _
       Left:=nLeft, _
       Top:=nTop)

       With oShape
           .TextEffect.NormalizedHeight = False
           .Line.Visible = False
           With .Fill
               .Visible = True
               .Solid
               .ForeColor.RGB = RGB(100, 100, 100)
               .Transparency = 0.5
           End With
           .Rotation = 315
           .LockAspectRatio = True
           .Height = CentimetersToPoints(2)
           .Width = CentimetersToPoints(15)
       End With

   End With

   For nCounter = 1 To nHowManyCopies
       oShape.TextEffect.Text = _
           sMyMessage & Str(nCounter)
           If bPrintOut Then
               ActiveDocument.PrintOut
           End If
   Next nCounter

End Sub

Hope this helps.

Shauna Kelly.  Microsoft MVP.
http://www.shaunakelly.com/word