Case statement in where clause

I'm trying to create a SSRS report for pulling employee records.

Depending on the parameter value for @workgroup at run-time, I want the query to select records based on specific status. I tried the below case statement in where clause but it is not working. 

-------------------------------------------

FROM
EMPLOYEE E

LEFT OUTER JOIN DEPT D
ON E.DEPT = D.CODE

LEFT OUTER JOIN ORGUNIT O
ON O.CODE = E.ORGUNIT

LEFT OUTER JOIN JOB J
ON E.JOB = J.CODE

WHERE

E.FLDWORKGRP = @workgroup AND

CASE WHEN @workgroup = 'Value' THEN E.STATUS = 'A' ELSE
E.STATUS IN ('A','N','LOA','P','D') END

ORDER BY E.LNAME

Let me know if there is any other way to do this. Thanks in advance for your help.