Document.Password Property (Word)
Published: July 16, 2012
Sets a password that must be supplied to open the specified document. Write-only String.
Avoid using hard-coded passwords in your applications. If a password is required in a procedure, request the password from the user, store it in a variable, and then use the variable in your code. For recommended best practices on how to do this, see Security Notes for Microsoft Office Solution Developers.