Continuing Paul's approach, I would suggest adding a sequence field rather than a fixed number. This way, if needed, you still rearrange the list.
Code:
Sub ScratchMacro()
'A basic Word macro coded by Greg Maxey
Dim oPar As Word.Paragraph
Dim oRng As Word.Range
For Each oPar In ActiveDocument.Range.Paragraphs
If Not oPar.Range.Words(1) Like vbCr Then
Set oRng = oPar.Range.Words(1)
oRng.Select
ActiveDocument.Fields.Add oRng, wdFieldSequence, "Numbered", False
End If
Next oPar
End Sub