We would need more information on what exactly you want to indicate if it is
possible or not.
Are you talking about a footnote version of the style rather than one where
all items are put into a bibliography at the end? If so, you could try the
style at
http://bibword.codeplex.com/Release/ProjectReleases.aspx?ReleaseId=20331 .
Note that it is still a beta version.
Or are you talking about a bibliography at the end but with numbers? Then
yes it is possible, but it will require XSLT knowledge to change the
existing style to support numbers instead. And how would you want your
numbers? If you want them ordered by occurence in the text, then the change
is pretty straightforward. If you want them to be ordered alphabetically at
the end, it will be rather difficult as Word does not provide such feature
directly. I found ways around it, but they require you to rewrite the style
in a specific way. As with your numbers you are already deviating from CMS,
you might be able to consider using the ISO 690 numerical style as an extra
deviation.
At
http://bibword.codeplex.com you can find several other styles which
support superscripted numbers, so maybe one of them is of interest to you.
At the very least they prove that superscripted numbered citations are
possible.
Yves