Simple customisation of Prestashop import tool

If you are familiar with presta theres a file called [login to view URL] wich handles import through backoffice. It handles products, attributes, customers, manufacturers etc. I need it's modification so that it can import features in the same manner as it does eg. attributes. I will create all necesary features manualy in BO and i need to fill database table ps_feature_product (maybe some others to?) with data. import shud be from csv in this manner: (product; feature,value; feature,value...) id_product ; id_feature, id_feature_value ; id_feature, id_feature_value ; id_feature, id_feature_value ... so i can set multiple features for same [login to view URL] i need that *.csv import reads products ID and to reckognise features by name and assign them to that product and to ignore potential empty fields in csv if theres any (and there probably will be). BR Sinisa