OK, what I'd suggest is creating a plain template with the following macro in it:
Code:
Sub PrintMe()
Application.ScreenUpdating = False
Dim iStart As Long, iEnd As Long, iCount As Long, StrPages As String
On Error GoTo Done
With ActiveDocument
iStart = .Sections.First.Headers(wdHeaderFooterPrimary).PageNumbers.StartingNumber
If iStart = 0 Then iStart = 1
iStart = InputBox("What is the First Number?", "Numbering Start From", iStart)
iEnd = InputBox("What is the Last Number?", "Numbering Stop At", iStart)
If IsNumeric(iStart) = False Or IsNumeric(iEnd) = False Then GoTo Done
If iStart > iEnd Or iEnd = 0 Then GoTo Done
iCount = iEnd - iStart
If Len(.Range.Text) > 1 Then
With .Styles("Page Number").Font
.Size = 16
.Name = "Arial"
.Bold = True
End With
.Range.Cut
With .Sections.First.Headers(wdHeaderFooterPrimary)
.Range.Paste
With .PageNumbers
.Add PageNumberAlignment:=wdAlignPageNumberRight, FirstPage:=True
.RestartNumberingAtSection = True
.StartingNumber = iStart
End With
End With
End If
For iCount = iStart To iEnd - 1
StrPages = StrPages & Chr(12)
Next iCount
.Range.InsertAfter StrPages
With Application.Dialogs(wdDialogFilePrint)
If .Show <> True Then iEnd = iStart - 1
End With
.Range.Delete
.Sections.First.Headers(wdHeaderFooterPrimary).PageNumbers.StartingNumber = iEnd + 1
End With
Done:
Application.ScreenUpdating = True
End Sub
(we can modify the wording etc. to meet your needs)
Then, whenever you get one of these labels generated by the external program, simply go to Developer|Document template and attach your template. If you then run the 'PrintMe' macro, that will take care of moving the content into the header and generating the pages. As written, the code allows you to re-use the document later on, though you will need to re-save it after attaching the template (which you only need do once) to keep the template attached.