Is there a way to insert a rich text box into a worksheet?

We need a box that basically works like a Word document - it will mostly be
used to created multi-level bullet lists in various font sizes with or
without bolding.

When looking at the Control Toolbox toolbar's "More Controls" button,
there's an option titled "Microsoft Rich Textbox Control 6.0 (SP4)" that
sounds like what we might want to use, but when we try to select it, we get
an error that says, "cannot insert object". As is typical with Microsoft's
generally useless help files, we can't find any more information about that
particular control, so we have no idea why Excel won't insert it. Any
thoughts or advise is appreciated!
--
Susan