An "Agilent 1260" is just the brand and model series number, not the name or revision of chromatography software that you are using. When you have a software question, it helps to specify it in detail. There are lots of different software systems out there which can acquire data from Agilent brand systems and few of them share common screens or even terminology.
As Ankita stated, no need to do anything custom, the software (tool) you need is right there in front of you. If you wish to view/print overlaid ("stacked") chromatograms or spectra, load them one-at-a-time (or as a group if you use the file select feature) using your CDS. The data analysis software has this common feature built-in. Just load the files, adjust the scales as needed and view. If you are unfamiliar with how to use the CDS software, then please obtain some formal training first. No one knows how to do these types of things without some professional training. There should be someone at your school who can help you.