Is there a way to maintain superscript when copy/pasting from word to inDesign?
Here's an answer you don't want....
In my experience, maintaining styles from Word can be problematic. What if you use a document font that doesn't contain a specific setting? i.e. Word uses "italic" but you use a font that uses "oblique". Or what if the Word document is using smart quotes and you want dumb quotes, or vice versa?
For a solid, well crafted text document I always save the Word file, whatever it is, to a plain text format. Thus stripping away all Word styling. I then use
File > Place to place that text document into InDesign and then go through reapplying character and/or paragraph styles as needed. I open the Word document on my left monitor for visual reference then work in InDesign on my primary monitor. In *many, many, many instances you may find that Word document had some odd "box" or callout that caused odd line breaks or issues with the import. So side-by-side comparison allows you to refine layouts as needed.
Why go to all this trouble? Well, it's not "trouble" in the grand scheme of things. By reworking the text in InDesign, you are somewhat obligated to pay closer attention to widows, orphans, page breaks, style application, special characters etc. Basically it kind of forces you to do a better job then you would if you copy/paste or slap some Word file into an InDesign document.
It doesn't take any extra time to use this method of reformatting than it does to hunt and seek for import errors and correct them. The only difference is a more confident, solid, final piece.
The best way to handle text import from Word to InDesign is to work up a WordBASIC macro which maps all formatting which one wishes to retain to suitable character and paragraph style and strips off all other formatting.
That way, the text imports cleanly and can be used w/o worrying about errant local formatting.