Add Signature Automatically in MS Word -- File Send as Attachment

I have a user who wants his signature to insert automatically when he sends a
Word Document using Word's -- File Send to -- As Attachment. The user has
his signature set to automatically appear on all new email messages as well
as any replies or items he forwards.

Is there a way to have the other MS applications read the default signature
options from Outlook when sending email from these applications.

Our current Mail format is HTML but I have also tried using Word as the
email editor...

Add Signature Automatically in MS Word -- File Send as Attachment