Como isso funciona? É uma macro, então adicione isso a um módulo no seu documento.
Sub add_hundreds_of_refs()
Dim myDoc As Document
Set myDoc = ActiveDocument
Dim i As Long
With myDoc
.MailMerge.Fields.Add Range:=Selection.Range, Name:="Code"
.MailMerge.Fields.Add Range:=Selection.Range, Name:="Type"
.MailMerge.Fields.Add Range:=Selection.Range, Name:="Amount"
Selection.TypeParagraph
For i = 1 To 200
.MailMerge.Fields.Add Range:=Selection.Range, Name:="Code" & i
.MailMerge.Fields.Add Range:=Selection.Range, Name:="Type" & i
.MailMerge.Fields.Add Range:=Selection.Range, Name:="Amount" & i
Selection.TypeParagraph
Next i
End With
End Sub