Returns or sets a String corresponding to the caption on a custom button on the Complete the merge step (step four) of the Mail Merge wizard. Read/write.
expression.ShowSendToCustom
expression Required. An expression that returns a MailMerge object.
When a user clicks the custom button, the MailMergeWizardSendToCustom event executes.
This example displays a custom button on the fourth step of the Mail Merge wizard.
Sub ShowCustomButton()
ActiveDocument.MailMerge.ShowSendToCustom = "Custom Label Processing"
End Sub