If there are multiple fields per query, you have four choices:

1) Use Switch. This works until you get too many fields, or too many values, or change values often. Any one of those conditions makes maintenance a bear.
2) Use subqueries in the field list. This works if the number of fields stays small; the number of values can be huge and change often.
3) Store the value as text instead of a number. This increases DB size but lowers query processing time. Why have a lookup table if it's not normalizing anything?
4) Write a VBA function and call it within the SQL. Not portable.

Pick one based on your environment.