I am having a hard time using MS Access because the syntax is a little finicky compared to other db's.
I am trying to validate a table and compare that table to a master table with multiple columns of information. At the moment I am trying to update a table with a field name of Difference_Value in table ct2011 to be equal to (ct2011.Distribution_Amount - AggregateFinal.SumOfDollars).
Also specifying the lines in which are going to be updated because not all rows in the MASTER are in the table ct2011. 
Below is my query.
UPDATE ct2011
SET ct2011.Difference_Value = (ct2011.Distribution_Amount - AggregateFinal.SumOfDollars)
FROM
       ct2011 as ct
INNER JOIN 
       AggregateFinal af
ON
       ct.Employee_ID = af.EmpId AND ct.Legal_Name = af.LegalName AND ct.Distribution_Plan_Year = af.CalculationAwardPeriod AND ct.Award_Year = af.AwardPeriod;
I am getting a Syntax error (missing operator). It specifies that it is encountering the error during the SET expressions after the =.
 
    