It's not clear from your question but I am going to assume you want to do this for a Word file as a Word macro, not an Excel macro.
One issue is that Excel has a SaveCopy method but Word does not. I have solved this problem in the past by saving the document, saving it with the new name, then re-opening the original. Also, the model in Word for handling a Save event is more complex than how it works in Excel. You can read that Microsoft page for details on capturing the event, then you can call the Sub below from it.
A simpler option might be to use the Windows file system to make the copy, rather than saving as a copy. I have not tested this but it illustrates the approach.
Bookmarks