First be sure the webmaster isn't hiding anything, simply what you want to do isn't that much used.
To download your GeneaNet index, click here :http://www.geneanet.org/geneweb/index.php3?download=1#down
At the bottom of the page, you are able to download a text file (use right-click). This text file is made with lines like that :
(name, occupation, extreme dates your surname was met, number of surnames, place, department, region, country, GeneaNet type of database)
All you will have to do next is to import or copy this text file in Excel, using the ";" as separators, each data will than be placed into columns.