defining range in sscanf()

in following code sscanf does not work properly :

It has some problems with [0-9]. could you please tell me why sscanf() doesn't work with [0-9].

int main()

{   

    char str[5][16] = {{0},{0},{0},{0},{0}};

    char pstring[128] = "user 12345 admin login password";

    sscanf( (Char *)pstring,"%s %[0-9] %s %s %s",
         str[0],str[1],str[2],str[3],str[4]);

    printf("%s\n",str[0]);
    printf("%s\n",str[1]);
    printf("%s\n",str[2]);
    printf("%s\n",str[3]);
    printf("%s\n",str[4]);

return 0;

}