Modificering af SQL streng

Jeg har af Terry fået lavet en SQL streng, som ser ud som følger:

SELECT DISTINCT Employees.Employeenumber, Employees.Employeename, Format([TimeStamp],"dd-mm-yyyy") AS [Time], (SELECT Format([TS1]![TimeStamp], "hh:mm:ss") FROM TimeStamps TS1 WHERE Format([TimeStamp] ,"dd-mm-yyyy") =  Format([TimeStamps]![TimeStamp] ,"dd-mm-yyyy") AND TS1.InOut = 'ind' AND TS1.Employeenumber = TimeStamps.Employeenumber) AS [In], (SELECT Format([TS1]![TimeStamp], "hh:mm:ss") FROM TimeStamps TS1 WHERE Format([TimeStamp] ,"dd-mm-yyyy") =  Format([TimeStamps]![TimeStamp] ,"dd-mm-yyyy") AND TS1.InOut = 'ud' AND TS1.Employeenumber = TimeStamps.Employeenumber) AS Out INTO TimeStamps2
FROM TimeStamps INNER JOIN Employees ON TimeStamps.EmployeeNumber = Employees.Employeenumber;

Nu vil jeg gerne have tilføjet et felt i den som indeholder Arbejdstid, dvs. Out - In.