Depending on whether your platform supports CASE construct
(Access doesn't)
Code:
SELECT CLAIMID,
'INDEMNITY' = CASE WHEN INDEMNITYRESERVED>NETINDEMNITY THEN INDEMNITYRESERVED ELSE NETINDEMNITY END,
'EXPENSES'= CASE WHEN EXPENSESRESERVED>NETEXPENSES THEN EXPENSESRESERVED ELSE NETEXPENSES END
FROM #TMPCLAIMS
WHERE (CASE WHEN INDEMNITYRESERVED>NETINDEMNITY THEN INDEMNITYRESERVED ELSE NETINDEMNITY END + CASE WHEN EXPENSESRESERVED>NETEXPENSES THEN EXPENSESRESERVED ELSE NETEXPENSES END)>500000
Of course, you don't need to include INDEMNITY and EXPENSES in the SELECT statement, I just put it there so you could see the values it would pull. You can delete that, and just leave the WHERE clause as is.