Excel 2007 : Plotting graphs with conditions?

Hi, I'm pretty new to using excel for any meaningful statistical purposes, but I'm doing a project as part of my course where I need to draw up some relationships for various sets of data.

I'm trying to get a graph that will plot the number or rate of false negatives of a medical test (which is worked out by the condition that it is given the text "negative" in one column, say column c, but "positive" in another, say column d), plotted against the age of the patient.

I'm not sure if this is even possible, as to my mind it will require linking contents of cells in different columns to each other, and I don't know how to do that..

At the moment I've just done it by working out the % of false negatives for different arbitrary age groups (eg >=65, <65 or >=50, <50), but I'd like to plot it in a graph somehow.

Any help would be greatly appreciated, thanks.

Thanks, I'm working on a summary table like that at the moment, but I was hoping there was a way I could take each individual case of a false negative, with the age of the person, rather than taking them in groups of age ranges if you know what I mean.