The document discusses how the author uses the VLOOKUP function in Microsoft Excel to filter raw measurement data and select only the relevant information. Specifically, it creates a lookup label column to identify sample peaks based on retention time. It then creates a new sheet where VLOOKUP looks up the labeled data, such as the filenames of chromatograms that contained a sample peak. This allows the desired data to be automatically selected rather than manually, saving time. Various other selections and filters are possible using VLOOKUP.