How to transcode UTF-8 csv file to be openable in Excel with a double-click (without any import special settings)?

I have the following CSV file: Hèllo,"ab - привет" (echo 'SMOobGxvLCJhYiAtINC/0YDQuNCy0LXRgiINCg==' | base64 --decode > bug.csv)

Opening it on Windows with Excel app via double-click, it shows the following: Hèllo ab - привет (but they are correctly placed in two columns).

If I do iconv -f utf-8 -t utf-16le bug.csv > bug_uft16le.csv and double-click, it shows the following: Hèllo ab - ?@825B, e.g. it correctly decoded Hèllo, but not the rest. (base64 bug_utf16le.csv: SADoAGwAbABvACwAIgBhAGIAIAAtACAAPwRABDgEMgQ1BEIEIgANAAoA).

If I do iconv -f utf-8 -t utf-16 bug.csv > bug_utf16.csv, Excel correctly shows Hèllo,"ab - привет", but it does not recognize that it should be two columns (base64 bug_utf16.csv: //5IAOgAbABsAG8ALAAiAGEAYgAgAC0AIAA/BEAEOAQyBDUEQgQiAA0ACgA=). bug_utf16.csv is exactly the same as bug_utf16le.csv but only has BOM as the file's first two bytes).

Is there a way to transcode a UTF-8 csv file so that Excel can open it, recognize the columns correctly (and keeping , as separator) and show all the French / Cyrillic script correctly?

I found a way sed s@","@"\t"@ bug.csv | iconv -f utf-8 -t utf-16 > bug_utf16_tab.csv, but I'd much prefer to not mess with replacing the separator (as it's brittle and may break around various quote escaping).

Thanks!

$ iconv --versioniconv (Ubuntu GLIBC 2.35-0ubuntu3.4) 2.35Copyright (C) 2022 Free Software Foundation, Inc.This is free software; see the source for copying conditions.  There is NOwarranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.Written by Ulrich Drepper.$ lsb_release -aNo LSB modules are available.Distributor ID: UbuntuDescription:    Ubuntu 22.04.3 LTSRelease:        22.04Codename:       jammy

UPD: it appears that one cannot force iconv to output BOM when transcoding to UTF8, as explained in this blog: https://zzz.buzz/2016/07/30/bom-in-iconv/