RExcel is an addin for Microsoft Excel. It allows access to the statistics package R from within Excel.
The main features are:
Data transfer (matrices and data frames) between R and Excel in both directions
Running R code directly from Excel ranges
Writing macros calling R to perform calculations without exposing R to the user
Calling R functions directly from cell formulas, using Excel's autoupdate mechanism to trigger recalculation by R
Using Excel as a GUI for R, making R functionality accessible through menus and dialog boxes instead of a command line oriented programming style. Using this paradigm, the widely used GUI package R Commander is available as an Excel menu bar.
Installed using the package RExcelInstaller from CRAN