ok. i found the solution. first i need to initialise the array items inside a function, otherwise it crashes
http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=301401#Post301401

then, of course!, i need to do
str_cpy(cuerpoSkins[i], file);
instead of
cuerpoSkins[i]= file;