Append Query And Auto Populate Field

I have a tbl that gets populated from an append query and a form that is crated from this table. there is one field that gets populated from the append query called departments, the department names are long and we have abbreviated versions of the department names that I would like to use.

In the table I have two columns “department” (for long name) and “updated department” (for abbreviated department name) When I use the append query to update the department (long name) I want the abbreviated department column to populate.

For example if department column reads "Drilling and Workover" from the append query, I want updated department column to slefpopulate to read "D&WO"

I want the updated department field to automatically fill with the abbreviated name. How do I do this?