How to install Scilab XLL Addin for Excel.
Launch Excel
Register the XLL with Excel, and you can do this in the UI by going to "File | Excel Options | Add-ins".
Drop down the Manage listbox, and select Excel Add-ins to display the Excel Add-ins dialog (not the COM Add-ins dialog).
Click the Browse button and navigate to the Scilab_XLL\bin\Scilab_XLL.xll to register this XLL with Excel. After this, you can go to the Formulas tab and click Insert Function you can see Scilab_XLL functions in the Insert Function wizard dialog.
To find where is Scilab_XLL.xll, if you have install with Atoms
packages=atomsGetInstalled();disp(packages(find(packages(:,1)=="Scilab_XLL"),4)+'\bin')