Is it possible to see the amount of ip addresses that are count by the ASA in order to order the correct user license for the CSC module ?
Yes but you have to 'sample' it over a reasonable period of time at the most probable 'peak time'. Netflow is the ideal tool for this but its not supported on any ASA except the 5580. You can also download a trial versio of fireplotter (fireplotter.com) for this purpose. It really helps in this regard.