I have converted the trigonometric functions presented in this earlier post into a Fortran dll.  The dll and associated spreadsheet and add-in files can be downloaded from here.

This file and the associated file Trig.dll provide trigonometric and hyperbolic functions not provided in VBA.
The functions are provided in two formats, either operating on a single value, or as an array formula.
“Degree” versions are also provided of all the trigonometric functions.
All the functions may be used either in VBA or directly in the worksheet, but the native Excel functions will be faster for spreadsheet use where available.
To install simply copy the dll file to your Windows/System32 folder and open the Trig Funcs.xls or xlsb file.

Introduction

List of Trig Functions

List of Hyperbolic Functions

Trig Function Examples

Hyperbolic Function Examples