i dont know if you can add to an actual .xcl file, but i DO know that if you add it to like a .txt or similar file you CAN then open it with excel
simply, add them in the following format:
entry1;entry2;entry3;etc
separate them by semi-colons (;)
if you want, i can write something very simple.. might take me a short while cuz i haven't scripted in a while
but if i were you, i'd find a simple form input script..
this sounds liek a simple job. i've done things VERY similar before