[DiapDealer]

Yes. The config dialog in the latest release of TagMechanic lets you add 'sup' to the list of tags available to change a span tag to. Config is a menu item (top left of the dialog).

Your vertical-align:super is probably part of a 'style' attribute value (it wouldn't really be valid xhtml any other way).

So after you add sup to your span config change_to list, you would:

choose 'Modify';
select the 'span' Tag;
Having the attribute 'style';
Whose value is (.*?)vertical-align:super (check the Regex box);
Change tag to 'sup';
and put class="noteref" in the New attribute string textbox.

And no: changing to tags with predefined attributes is not in the cards for this plugin. It's not really necessary given that you can already define the entire attribute string of the tag you're changing to.