Numbers.dll had been released as public domain by it's author.
Hobbes: http://hobbes.nmsu.edu/h-search.php?key=Numbers-1_2.zip
"Numbers.dll is a DLL that implements a REXX function (Number) for OS/2 that returns on number expressed in cardinals, it est, in letters, in English, Catalan or Spanish; for Catalan and Spanish languages the number can be obtained in masculine or feminine. Released as Public Domain Software."
The source code is also on GitHub: https://github.com/OS2World/LIB-REXX-Numbers
Thanks to it's author, Gabriel Massip Fons, for releasing the source code of it.