Since a SolidWorks part is limited to a 1 km cubem you are going to have to convert the latitude and longitude before you import the data points.
I saw the excel. As Jerry said there is limitation of 1Km. Also he is right that you will have convert these into XYZ co-ordinates.
- You can use some tool to covert these points into XYZ like https://www.ngs.noaa.gov/cgi-bin/xyz_getxyz.prl
- Then in excel itself divid the XYZ values by common factor ....say 1000 for example (This can also be achieved by selecting smaller unit in document settings). Now you have smaller values that you can be used to construct Curve through point. or http://grabcad.com/questions/tutorial-how-to-import-points-to-solidworks-from-a-text-file
Hope this is useful!