Excel Cubic Spline
This workbook contains a VBA code module that adds a cubic spline function to MS-Excel. It also includes a useful utility for automatically copying the code module into other workbooks. The cubic spline function smoothly interpolates between data.
Appears to work exactly as advertised. The spline function lets one specify the x and y ranges to be fit. I was able to use after a few minutes of looking at the example workbook.
