An Excel command macro has been developed which directly transforms X-ray powder diffraction data to a spreadsheet format. This spreadsheet format offers a number of data reduction and plotting capabilities not available in a diffractometer's software. The conventional approach uses computer programs to transform the data outside a spreadsheet. The development of these programs is not a simple process, and requires the user to be familiar with computer programming and the software of a diffractometer. Furthermore, these programs are diffractometer-specific. A different approach is followed in which an Excel macro transforms the data within a spreadsheet. This macro, with minor modifications, can be applied generally to treat data from any diffractometer. A copy of the macro and an example illustrating its working principle are included.