Breakout Query For Prices

I am trying to write a breakout formula to identify if today's close is greater than the maximum close of the last 20 days. This is what I have so far:

SELECT WZ07.Symbol, WZ07.AlphaDeliveryMonth, DateSerial(Val(Left([ddate],4)),Val(Mid([ddate],5,2)),Val(Right([ddate],2))) AS transdate, WZ07.DClose
FROM WZ07
WHERE (((DateSerial(Val(Left([ddate],4)),Val(Mid([ddate],5,2)),Val(Right([ddate],2)))) Between Date()-28 And Date()-1) AND ((WZ07.DClose)=(select max([WZ07].DClose) from [WZ07])));


If I replace the = symbol with a > symbol near the end will it compare today's close to the max of the date range selected? I thought I had this figured out but apparently not.

I can do a query that will give me the last 20 days using the "Between date()-28 and date()-1 criteria. I can do a separate query for the maximum close using select max([WZ07].DClose) from [WZ07] but when I try to put them together it screws up. I need to have it first do the last 20 days query and then take the maximum close from it, and then compare to see if today's close is greater than that number. Can this all be put together? Thanks for your help.