Need Help with a Random Number Generator with Weighted Probability for Certain Numbers

Friends,

I have a workbook with around 200 items, indexed from 1 to 200.

I need excel to generate several random numbers from this list...

BUT...

Certain items in the list need to be more likely to be generated. I was thinking of a assigning an "Importance Factor" of sorts to certain items in the list which would alter the likelyhood of that item's index number being selected.

Does anyone have any ideas?

Normally the basic idea is that each item in a set has a equal probability of getting picked at random. If you want some items to have a greater probability of being picked, you need to assign them more slots.

For example, if A = 10% chance, B = 20% chance, C = 30% chance, & D = 40% chance.

Then you generate a random number for 1 to 10, and assign A to 1, B to 2 & 3, C to 4-6, and D to 7-10.

Your problem isn't that much different. You just need to figure out how much more important some items are compared to the rest. Are they twice as important? What?