I looked into the answer from Máta whose name hints at encoding qualifications and experience. The VBA docs say CreateTextFile(filename, [overwrite [, unicode]])
creates a file "as a Unicode or ASCII file. The value is True if the file is created as a Unicode file; False if it's created as an ASCII file. If omitted, an ASCII file is assumed." It's fine that a file stores unicode characters, but in what encoding? Unencoded unicode can't be represented in a file.
The VBA doc page for OpenTextFile(filename[, iomode[, create[, format]]])
offers a third option for the format:
Máta passes -1 for this argument.
Judging from VB.NET documentation (not VBA but I think reflects realities about how underlying Windows OS represents unicode strings and echoes up into MS Office, I don't know) the system default is an encoding using 1 byte/unicode character using an ANSI code page for the locale. UnicodeEncoding
is UTF-16. The docs also describe UTF-8 is also a "Unicode encoding," which makes sense to me. But I don't yet know how to specify UTF-8 for VBA output nor be confident that the data I write to disk with the OpenTextFile(,,,1) is UTF-16 encoded. Tamalek's post is helpful.