Ladder spreadsheet (calculator)

[NinjaLizard]

Hi I'm trying to create a ladder type calculator similar to the ladder found in the bet angel software but I'm struggling with the very basics. I want to include 4 columns lay, odds, back then profit/loss with the idea of dropping a stake in either the back or lay column and having the hedged value at each price displayed in the profit/loss column. If anyone could point me in the right direction as to how to go about this I would very much appreciate it. Also I realise the creation of such a calculator could be long winded so don't feel obliged to explain as I am a dummy when it comes to this type of thing.