Can't do that. ID can't find "other" attributes, only specified ones.
This one regularly bites me when authors don't use Superscript and Subscript, but make their text a few pts smaller and move it up/down a few points -- and I bet it's their (w|W)ord processor that does it!
"A" solution (as opposed to "the") is to mark all 'good' text with S&R with a color, then search for orginally-colored text.
.. Although, in your case, I think you can set all kerning to 0 and be done with it.