Selecting a worksheet based on cell value

[croix]

I am trying to automatically select data from a different sheet to fill data in a cell based on two other cells. I've attached a simplified version of what I'm trying to do (with detailed explanations). I hope it has enough info to get my point across.

I posted this in the "programming" forum because I'm pretty sure I will need to use vba in some form or fashion to get this to work. I am more familiar with access than excel, so I may be missing some easier way to make excel do this.

Thanks,