If a very large formula is required for a named range, how does one go about
editing it on the Define Name dialogue?

I've been writing the formula in notepad, then pasting the whole thing into
the text box. Every time I try to move the cursor along in the text box with
the arrow keys, Excel thinks I am tying to add data to the formula when all I
really want to do is see the parts of the formula beyond the edge of the text
box. The Define Name panel cannot be sized to allow the whole formula to be
seen.

Thanks for any help.