if statement in SQL to calculate age

I am very new at SQL and I have been working on my First Query. Now I need your help. I have this report in Excel. I have formula in the AGE column N calculating the AGE. I have been trying to create a SQL query to come up with the same answer. So far I have figured out the columns that I need and pulled all the data to Match Excel. Only thing is I don't know how and where to enter this IF statement so it will calculate the age when i run the query.

Work Order  Location    MISC    Status  Actual Finish   Finish Time Parent WO   Work Type   N   Reported Date   Reported Time   Site    Gen Age Sub Name    Substation Location                         
1234567899  4074        COMP    11/5/14 3:08:49 PM      CM      10/7/14 1:47:42 PM          29.05633102                                 
12348574987 2946        SCHED               CM      10/30/14    10:28:03 AM         188.5638542     

AGE is a formula, pasted below:

=IF ((IF(Status<>"Comp",Today()-Reported date, actual finish-reported date))<0,0, IF(STATUS<>"COMP", TODAY()-REPORTED DATE, ACTUAL FINISH-REPORTED DATE))       

SQL Writen Query

SELECT WO.WONUM,                                                                                        
  LOCOFFDESC.DESCRIPTION AS OFFICE,                                                                                     
  WO.STATUS,                                                                                        
  WO.LOCATION,                                                                                      
  CASE                                                                                      
    WHEN ((INSTR(LOCOFF.EXT_LOC_HIERARCHY_PATH, '/', 2, 3)) = 0)                                                                                        
    THEN SUBSTR(LOCOFF.EXT_LOC_HIERARCHY_PATH, ((INSTR(LOCOFF.EXT_LOC_HIERARCHY_PATH, '/', 1, 2) + 2)), LENGTH(LOCOFF.EXT_LOC_HIERARCHY_PATH))                                                                                      
    WHEN ((INSTR(LOCOFF.EXT_LOC_HIERARCHY_PATH, '/', 2, 3)) IS NOT NULL)                                                                                        
    THEN SUBSTR(LOCOFF.EXT_LOC_HIERARCHY_PATH, ((INSTR(LOCOFF.EXT_LOC_HIERARCHY_PATH, '/', 1, 2) + 2)), (INSTR(LOCOFF.EXT_LOC_HIERARCHY_PATH, '/', 2, 3)) - (INSTR(LOCOFF.EXT_LOC_HIERARCHY_PATH, '/', 1, 2) + 2))                                                                                      
  END AS "SUBSTATION CASE",                                                                                     
  WO.PARENT,                                                                                        
  WO.WORKTYPE,                                                                                      
  WO.REPORTEDBY,                                                                                        
  WO.REPORTDATE,                                                                                        
  WO.ACTFINISH,                                                                                     
  WO.SITEID                                                                                     
FROM LOCATIONS LOCOFF                                                                                       
RIGHT JOIN MAXPRD.WORKORDER WO                                                                                      
ON WO.LOCATION = LOCOFF.LOCATION                                                                                        
INNER JOIN MAXPRD.LOCANCESTOR LOCOFFANC                                                                                     
ON LOCOFFANC.LOCATION = LOCOFF.LOCATION                                                                                     
INNER JOIN MAXPRD.LOCATIONS LOCOFFDESC                                                                                      
ON LOCOFFANC.ANCESTOR = LOCOFFDESC.LOCATION                                                                                     
INNER JOIN MAXPRD.LOCHIERARCHY LOCOFFHIER                                                                                       
ON LOCOFFANC.ANCESTOR = LOCOFFHIER.LOCATION                                                                                     
WHERE LOCOFF.SITEID   = 'SUB'                                                                                       
AND LOCOFFHIER.PARENT = '2000'                                                                                      
GROUP BY WO.WONUM,                                                                                      
  LOCOFFDESC.DESCRIPTION,                                                                                       
  WO.STATUS,                                                                                        
  WO.LOCATION,                                                                                      
  LOCOFF.EXT_LOC_HIERARCHY_PATH,                                                                                        
  LOCOFF.SITEID,                                                                                        
  LOCOFFHIER.PARENT,                                                                                        
  WO.PARENT,                                                                                        
  WO.WORKTYPE,                                                                                      
  WO.REPORTEDBY,                                                                                        
  WO.REPORTDATE,                                                                                        
  WO.ACTFINISH,                                                                                     
  WO.SITEID