This is a common function in application systems, and I am sure there is
a simple way to do it in Excel, but so far I haven't been smart enough
to figure it out.

I have a column of account codes on Worksheet 1. I want to be able to
select a code cell, open Worksheet 2 containing one column for all valid
codes and one column for the descriptions, select a code from Worksheet
2 and have it automatically inserted into the code cell of Worksheet 1.

Thanks for your help.