Lookup Using List - Change Search Criteria

Wishing to be able to change default search field for a referenced field.

For example...
On any form that references the CMDB_CI table, have the default search/auto-complete use the serial number instead of the name. The form would just show the serial number field of the CMDB item.

Seems like there should be an easy way to change the default behavior of the display and search value... Dictionary Override?

Thanks in advance

Ron