It is possible to add subscripts and superscripts, but you would need to use HTML in order to do this. Here is the code you would use:
<span style="vertical-align: super;">Superscript Text, </span>Normal Text, <span style="vertical-align: sub;">Subscript Text</span>
You will need to edit the words "Superscript Text" and " Subscript Text".
For information on how to add the HTML code to your site, please click here.