Help w/ Excel spreadsheet & probability

Hi. I am trying to make a spreadsheet to calculate the likelihood of certain items appearing in a game called Monster Hunter Tri for the Wii (hopefully some of you have played it)

Basically this is what happens:

When you kill a monster, you get to "carve" its body 3 times. There are certain items you can get from this, all of which have their own probabilities. Then you get 5 items for completing the quest, again, each item with its own probability. Then, if you succeeded in "breaking" a part of the monsters body, there is a chance for even MORE items. etc.

So I want to be able to calculate the total % chance of getting an item once, twice, three times, etc.

Here's what I've made so far, in excel. See if you think the current numbers are correct.

http://img208.imageshack.us/img208/653/probab5.png

So to remind you.

Body carves you get 3

Quest Rewards = 5

Tail Carves = 1

Shiny Drop = 1

Destroy Body Part = 1 per body part

For example, if I beat this monster (lagiacrus) and I do EVERYTHING possible meaning I kill him, do the quest, get a shiny drop and break all of his body parts, what are the chances I get 1 Lagiacrus Hide, 2 Lagiacrus Hides, 3, etc., for each item?