Document.SetLetterContent (Word)

Inserts the contents of the specified LetterContent object into a document.

This method is similar to the RunLetterWizard method except that it doesn't display the Letter Wizard dialog box. The method adds, deletes, or restyles letter elements in the specified document based on the contents of the LetterContent object.

SetLetterContent (LetterContent)

LetterContent: The that includes the various elements of the letter.

Set myLetterContent = ActiveDocument.GetLetterContent 
myLetterContent.AttentionLine = "Greetings" 
ActiveDocument.SetLetterContent LetterContent:=myLetterContent