You can change the query into a Make-Table Query to create a temporary table:
SELECT Shift.Shift_ID, Shift.Shift_Type, Sum(Main.Shift) AS SumOfShift, Format([Date],"mmmm") AS Expr3, Year([Date]) AS Expr4 INTO tblTemp
FROM Shift INNER JOIN Main ON Shift.Shift_ID = Main.Shift
WHERE...