UTF8 encoding failure writing text file from Word VBA - vba

Question

I am using MS Word to edit text that I convert to structured HTML using VBA.
The text is written out using document.saveas2 with encoding:=msoEncodingUTF8.
Today I found that the Trademark Symbol [Edit: inserted using the Insert Symbol capability; Insert Tab, Symbols group, Symbol button] was appearing in the text files as "(tm)".
Having discovered that encoding:=65001 should also produce UTF8, I tried it - and in one case it seemed to work, but the result was not reproducible.
I also learned that being older than Unicode, Word might use a private code page for certain characters, so I also entered the unicode code directly followed by alt-X; the TM symbol appeared correctly but still failed to be written to the text file.
Whilst I have been able to work around the problem by replacing TM with the HTML "& trade ;" (extra spaces to prevent it getting rendered as the symbol!), I am concerned about the potential for other encoding failures.
Can anyone shed any light on the cause(s) of this issue or offer an effective resolution/mitigation?
System config: Word 2010; Windows 7 64 bit.

Answer 1

I recorded a macro to save some some Chinese text that is clearly unsupported in the default code page on my system, which was Windows-1252. I saved in .txt format and it asked for the encoding, which I selected UTF-8. Here is the result:
ActiveDocument.SaveAs2 FileName:="The.txt", FileFormat:=wdFormatText, _
LockComments:=False, Password:="", AddToRecentFiles:=True, WritePassword _
:="", ReadOnlyRecommended:=False, EmbedTrueTypeFonts:=False, _
SaveNativePictureFormat:=False, SaveFormsData:=False, SaveAsAOCELetter:= _
False, Encoding:=65001, InsertLineBreaks:=False, AllowSubstitutions:= _
False, LineEnding:=wdCRLF, CompatibilityMode:=0
It did save the file correctly in UTF-8. I edited the macro down to the following minimal code and it still worked.
ActiveDocument.SaveAs2 FileName:="test.txt", FileFormat:=wdFormatText, _
AllowSubstitutions:=False, Encoding:=65001

Answer 2

I wanted to save in filtered html utf8, so I tried:
doc.SaveAs2 FileName:="file1.htm", FileFormat:=wdFormatFilteredHTML, AllowSubstitutions:=False, Encoding = msoEncodingUTF8
I found that although with FileFormat:=wdFormatText the file did save in utf8, doing the same with wdFormatFilteredHTML did not.
What did work was
doc.WebOptions.Encoding = msoEncodingUTF8
doc.SaveAs2 FileName:="file1.htm", FileFormat:=wdFormatFilteredHTML, AllowSubstitutions:=False