HeaderSourceName Property
Returns the path and file name of the header source attached to the specified mail merge main document. Read-only String.
Example
If a header source is attached to the active document, this example displays the file name.
Dim strName As String
strName = ActiveDocument.MailMerge.DataSource.HeaderSourceName
If strName <> "" Then MsgBox strName
This example opens the header source attached to the active document if the source is a Word document.
Dim mmdsTemp As MailMergeDataSource
Set mmdsTemp = ActiveDocument.MailMerge.DataSource
If mmdsTemp.HeaderSourceType = wdMergeInfoFromWord Then
Documents.Open FileName:=mmdsTemp.HeaderSourceName
End If