High/Low formula that resets after finding previous low - stock trading

As the title suggests I am looking for a way to search a string of data (ie the closing price of a stock) for the highest and lowest price. That in itself is simple. The part that I am struggling with is getting excel to reset the parameters of the search to update so that after a high or low is found excel searches for the next subsequent low or high. Not to be confused with the next lowest or highest number in the string but by only looking forward from the previous high or low as daily closing prices are added to the data string. I hope I am explaining my needs correctly. I want to use this to generate buy and sell signals as highs and lows are reached while tracking a trend in a given stock as it climbs or descends. For example: A up trending stock I feel that the new highs will be relatively simple to track but as the low increases I need to find a way to pick it out of a large string of data even though it is only the low for a smaller period until a new low is established (higher or lower than the previous low). I would like to make this automated. I can struggle though resetting formulas and changing data fields manual but this is a lot of work when tracking a dozen stocks or more. I appreciate any and all suggestions. OH and btw I did do a comprehensive search prior to posting and did not find what I was looking for.