This meta question is somewhat similar to this other meta question - both about flagging your own posts, though my situation is a bit different and I'm not sure whether the given meta answer is applicable in my case.
I originally posted my question "Excel like column numbering" on PE site. After it was migrated to CR I almost immediately noticed that among "Similar Questions" there was almost a "twin" question with the answer that was quite acceptable to my case. I already posted a comment in this regard.
I would like to keep my question and just flag it as a duplicate. Is it acceptable?
I obviously do not want to post a self-answer even with a proper attribution of the solution.