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Sets an alias for a filename used in any of the GET XLS…or GET 123... functions. When the filename specified by ?alias is encountered the filename filename.xls will be substituted. The alias term must begin with a ?, and you can use just a ? (or a blank) for the empty alias reference. If filename is empty any alias that did exist will be removed (so that the user will be prompted for a filename when the model is run).