RagDyer wrote

Try using single or double*accounting* underline.

Funny thing about this is, although it's called accounting, if you
enter a number in the cell, the underline does *not* extend the full
width of the cell.
Text will make it go the full width.
Also, entering a number with an apostrophe prefix, or *pre-formatting*
the cell to Text, will allow it to fill the entire width when using
numbers.

I've found, in XL2K at least, that accounting underlines do not extend the
*full* width of the cell.

--
David