Link field in the lookup wizard

I am using the the lookup wizard to display a list of usernames from the admin_users table. When a name is selected and saved I would like the data from another field in the admin_users table to be displayed. The admin_users table has no link to the table I am using to produce the view of the form template. Is there a way to do this?

Whether you use dependent dropdown feature or code, you will need some kind of link between the two tables, and ID number, project number etc. - can you post an example including some details and sample of each field ?