Regression analysis and 3-D surface plotting

[Peter-PC3]

I have some data, two independent variables (input factors x,y axes) and one dependent variable (a response output variable z axis) and I would like to fit a model and plot a 3-D surface representing this data.
So my first question is can the data analysis pack in Excel handle this regression analysis, or do I need to use a statistical package like PSPP?

If Excel can handle this, how do I go about doing it?

Thanks for any comments or suggestions.

Peter

[#2]

Excel can handle the regression analysis alright, but its surface chart expects equally-spaced x and y data (1, 2, 3, 4, 5, ...).
This means each subsequent input variable must have the same difference with its predecessor.

[#3]

@Jan Karel Pieterse 

Thanks very much that's very helpful Jan. I just need to figure out how to do the analysis in Excel. Once I have I think that I should be able to use the model to produce a set of x,y values that are evenly spaced for input into a chart. Peter