Excel Graph Help - Determining Peaks

I have made various plots in Microsoft Excel of periodic wave action and would like to know of a quick way of determining the values of all the peaks. Sorting the values in the spreadsheet is not an option because some peaks are much higher than others, and would not give just a list of 10 or so peak values. Can anybody help me with this? Obviously I could go manually looking for the peak values of each graph but because of the large volumes of these graphs we will have, I want to find a quicker method. So, what I would like is a list of min and max values from a graph, with none of the other high values.

Any help would be great!

many thanks

Rob