Multiple Criteria (add or subtract)

I am working on a stock trading sheet that is checking on several paramaters like volume, change in price today vs change in price yesterday, and price moving above or below a trading channel. This is a back testing process working from historical data downloaded from the yahoo stock site.

What would the best process be to quary all of the paramaters above and when each is true issue a "Buy" signal and start accumilating "Profits" untill the sheets hits a new criteria for "Sell".

I want to calculate the profit or loss based upon the change in stock price between two sets of multiple criteria. Addationally I want the sheet to issue one of three positions based upon the most current state of the markers checked: Buy, Sell or Hold.

Not looking for specific answer just a point me to the correct excel function.

Thanks, Michael

SUMPRODUCT is a good formula
=IF(SUMPRODUCT((A1:A100>200)*(B1:B100<400)*(...))>0,...)

Another useful approach is to use CHOOSE
=CHOOSE(1+(A1>200)*1+(B1>400)*1,"Buy","Hold","Sell")

Hope this helps
Ola Sandström