I want to either italic or underline, or superscript part of the textbox, but
not the whole thing. How do I do this?

For example, I want "this is: an example" to have italics on 'this is' but
not on 'an example'. Left clicking does not have format cells as an option
when I have selected part of the text in the cell. However, it is an option
if I have simply selected the entire cell.

Also, is there a way to do a hard return within a single cell of text for
excel? This question would be less useful for me than the first.

Thanks so much in advance!