If each line starts with A2 then
Code:
Sub FixReferences1()
Dim oRng As Range
Set oRng = ActiveDocument.Range
With oRng.Find
.ClearFormatting
.Replacement.ClearFormatting
.Replacement.Font.Bold = False
.Text = " A2"
.Replacement.Text = "^pA2"
.Forward = True
.Wrap = wdFindContinue
.Format = True
.MatchCase = False
.MatchWholeWord = False
.MatchAllWordForms = False
.MatchSoundsLike = False
.MatchWildcards = False
.Execute Replace:=wdReplaceAll
End With
End Sub