Can you user CASE in SQL object?

I have a SQL object with

SELECT CASE WHEN C.PERIOD_TO > 6 THEN A.FISCAL_YEAR ELSE A.FISCAL_YEAR + 1 END AS FISCAL_YEAR ,C.PERIOD_TO ,C.NO_OF_WEEKS ,NVL(A.DEPTID ,'NOFUNCAREA') ,A.ACCOUNT ,A.BUSINESS_UNIT ,A.USF_ACCOUNTABLE ,ROUND((DECODE(SUM( A.POSTED_TOTAL_AMT) , '-0' , 0 , SUM( A.POSTED_TOTAL_AMT)) ) , 4) FROM PS_USF_ACCOUNTABLE A , PS_GL_ACCOUNT_TBL B , PS_SET_CNTRL_REC B2 , PS_USF_SYS_CAL_WK C WHERE B.ACCOUNT = A.ACCOUNT AND B2.SETCNTRLVALUE = A.BUSINESS_UNIT AND B2.RECNAME = 'GL_ACCOUNT_TBL' AND B2.SETID = B.SETID AND C.SETID = 'TST' AND A.ACCOUNTING_PERIOD = C.PERIOD_FROM AND A.WEEK = C.WEEKOFMONTH AND ((A.ACCOUNT BETWEEN '1000000' AND '8999999') OR A.ACCOUNT LIKE '9%') AND A.LEDGER = 'TEST01' AND B.EFFDT = ( SELECT MAX(B_ED.EFFDT) FROM PS_GL_ACCOUNT_TBL B_ED WHERE B.SETID =