Trendline Approximation

[Drazick]

Hello.

I found the Trendline function in Charts very useful.

My question is: Are there equivalent functions?

What I mean, I know about "Trend" and "Linset" functions.

Yet in Trendline there are Polynomial Approximations, Exponential Approximations etc...

Which I couldn't find anywhere.

Are they available? How can I create the dataset according to Excel approximation (I want cells with the data instead of the chart)?

Are there anymore Approxiamtions / Interpolations in Excel (Splines, Least Squares, etc..)?

I'm using Office 2007.

Thanks.