Effective Interest Rate formula

Hi guys,
My Accounts department have asked me to find out how to convert a mathematical formula into an Excel formula.
I'm a bit stuck, as the descriptive text for the mathematical formula doesn't even make sense to me!
I've attached it as a jpg attachment, in which the text is as follows :

The effective interest rate can be computed using a calculator or spreadsheet program. In mathematical terms, the effective interest is found by setting up this equation and solving for the interest rate (y) that equates (1) the initial carrying amount of the asset or liability (PV) with (2) the present value of the estimated future interest and principal cash flows (CF) in each period (i).
In some cases, the effective interest rate will equal the stated interest rate of the asset or liability. This is often the case for loans and long-term note receivables or payables where the initial proceeds equals the principal and the entity was party to the contractual terms at its inception. For such assets, amortized cost equals cost and will be the same in each period. In other cases, the effective interest rate differs from the stated interest rate. This is the case when a debt security is purchased or issued at a premium (higher price) or discount (lower price) to the stated principal (par) amount. In those cases, it is usually necessary to compute the effective interest rate and prepare an amortization schedule in order to determine amortized cost in each period.



If you're still reading, you must have a better idea of what's going on than me!

So, if anyone here is a financial whizz and think you can make sense of this, I'll be in your debt forever*

*not really, but I will be extremely grateful.

Many thanks,
Jon