I have a spreadsheet that calculates up to 10-way ICM equity, but I can't find the link I downloaded it from.
It's designed (by 'SmallPotJeff'?) for deal making, but you can do this math with it, too. Use this to calculate equity now and with your 'win' stack, sngpt will give you the 'win %', and then do the math yourself.
If you want it, PM me your email address or tell me how to upload it somewhere.