Update: In the case, you want to work with GPX files directly in Excel, see also this post. From version 2.0 you can work with GPX files directly, without external third-party programs.
For hydrogeological mapping I use the GPS device that saves me route into GPX files. These data I use for the research in the field. GIS.XL in 1.0 version does not support direct work with GPX files. For converting to readable format can be used an online GPX converter - www.gpsvisualizer.com.
After conversion you can paste table data into the Excel spreadsheet. Practical example displays the following video. Converted data is loaded into the Excel as a simple table. Track points can be displayed in the Map Panel along with other attribute data.
Trackpoints you can inset to Map Panel in the form of point or line features. For line features you must set one extra parameter. Coordinates of individual line vertexes are stored in two columns (X and Y). If you are creating only one linear object, it is not necessary to set the Line ID property and all coordinates will create only one line.
For layer with multiple line features, you must set the “Grouping Column” property (one column in Excel table). Each individual line is created unless the value in specified column changes. The Grouping Column may contains date, number or string values.
If new line layer is created (displayed in the Map Panel), you can save it as a shapefile to your disk or you can export it to Google Earth as a KML file (GPX to KML).