Help with Microsoft Excel

I was wondering if anybody would be willing to assist me with entering formulae into microsoft excel.
I'm not talking about the basic stuff like addition, multiplication, etc. I require assistance with equations and formulas regarding acoustics, ie transmission coefficients, absorbtion, etc. I've got a few of them sussed, but one, (LOGINV) in particular is proving to be more pain to me than I can handle just now!
I dont want to pay somebody a load of money to go on a course, when all I need to know is entering formulae!

Any suggestions would be helpfull, or even links to sites that give help regarding this! I've checked out a few that I've found through google, but they only give help with the basic stuff!

Thank You in advance

try here

http://www.ozgrid.com/forum/

This is from the Microsoft web site - hope it is of some use
http://office.microsoft.com/en-gb/as...091611033.aspx

Thankx guys, but still not what I'm after! Oh well!