I have a column of data that is selected using a dropdown box. The
value placed here is looked up by the adjacent column to display some
text corresponding to the first. --let me try to be more specific
for clarity -- When I select a diagnostic number in column A, the
corresponding text appears in column B.

There are times when I cannot remember the number for a particular
diagnosis, and want to instead use a dropdown list on column B which
would result in the number appearing automatically in column A.

I don't think this is possible without scripts. Can anyone get me
started on this? I'm thinking I need to put drop down boxes on both
columns and then have changes to A trigger an update to B, and B
trigger an update to A.

Can anyone get me started with an elegant solution?