Also, you could think about using a Switch statement,
SELECT JobNumber, SubPreFix, CTCDTE, LastOfInvDate, NvNoTax, DSCRPT,
Switch([SubPreFix] In (3007,3008,3090) And [DSCRPT] Like "*Lot Clean 1*","EC1", [SubPreFix] In (3007,3008,3090) And [DSCRPT] Like "*Lot Clean 2*", "EC2", [SubPreFix] In...