Salutations,
Under the File I/O section there is a VI called the "Read from spreadsheet file.vi". I'd suggest saving your xls file as a CSV file (do a "save as" and make sure to say .csv instead of .xls - sometimes you'll lose formating) and then using the deliminator as a ",". If you look over that vi, you should be able to grab your desired data. Now you've got a 2-D array, so index the array (could use controls to switch it up - while loop and event structures to mess around with what is plotted) so that you get the 2 columns or rows that you desire, "bundle" them together using a "cluster" and plot them into an X-Y graph.
Now, if you want to plot multiple x-y plots, you're capable of doing that as well. Look over the x-y graph help, it'll tell you how to properly cluster and build (build array - wire in the clusters) the desired inputs. That's just about all you need really.
Of course, your X and Y array must be of the same size.
That should get you into what you desire. Now if you want to start getting fancy, investigate the use of property nodes to control the looks of your plot etc...
Sincerely,
ElSmitho
