expression.DataFieldIndex
expression Required. An expression that returns one of the objects in the Applies To list.
Example
This example maps the PostalAddress1 field in the data source to the wdAddress1 mapped data field. This example assumes that the current document is a mail merge document.
Sub MapField()
With ThisDocument.MailMerge.DataSource
.MappedDataFields(wdAddress1).DataFieldIndex = _
.FieldNames("PostalAddress1").Index
End With
End Sub