Case Statement in SQL Delminted Query

I have the following case statement in my sql delimited query:
       ||(CASE
          WHEN emp.emp_status in ('FB','PN','PB','LW','LP','LS','LT','LE','LI','WA') THEN 'A'
          WHEN emp.emp_status in ('LF','LM','LO','LU','LA','LR') THEN 'L'
           ELSE null
          END

Although the result is just 1 character, per the vendor spec, it needs to be a length of 20.
How would I write that?