numbered citations need a unique number for each one

Hello, I am using Chicago style on Word for Mac and want each of my numbered citations to have its own number, even if it is a repeated citation. Right now, if I repeat a citation later in the text it will be given the same superscript number as the earlier citation but I want it to have its own number. Can someone tell me how to do that?
Thanks!!

Why?  I don’t think this is possible.  You could consider using footnotes instead? 

Thanks for responding so quickly. I need to provide both a list of footnotes numbered reference (as endnotes at the end of the chapter, actually) and then a full bibliography in alphabetical order at the end of the book. I want the endnotes to have each author listed separately with its own number (rather than having one number for each reference to the author in the text). The second and third time the author is cited would have a “shorted version” as per Chicago style.

That is precisely the way the Chicago 16th A style works I believe.  You use word to insert the footnote and add the citation to the footnote.  It is set up to use the full citation the first time and a shorter version the subsequent footnotes containing the same citation (assuming it isn’t the NEXT footnote, which is set up as ibid).  It also produces a bibliography at the end, in alpha order -