AstroExcel is a spreadsheet, it doesn’t require any special plug-in’s however you will need to enable macros to use the functions. If you are at all concerned please configure your Excel to show the developer tab and then open visual basic from here you can view all the source code.
Latest stable version:
Corrrected Messier RA data
Fixes a bug in MoonPhaseDate()
v20151011 adds 2 functions…
RaDec() this calculates the RA and Dec from the Altitude and Azimuth
MoonRise() this calculates the rise, transit and set of the Moon.