Thanks for both suggestions.
I am correcting OCRed text in the Cyrillic alphabet, but I am not proficient in using the Windows Russian keyboard. An insertion can be one or more Cyrillic letters. If I understand LO macros correctly, I don’t think they would be suitable for this purpose.
I have been using BabelMap — similar to the Windows Character Map — however neither of these writes straight to a document but requires copy and paste. So I thought LO’s “Insert Special Character” (ISC), which does write straight to the document, might be less trouble.
The “double-click” advice is good, and solves the problem of inserting a sequence of characters. But when I have inserted one sequence, the focus does not return to the document without closing the ISC window. Then it has to be reopened for the next insertion.
For me, ideally, the ISC window should accumulate the chosen characters in a buffer (as CharMap does), and transfer the sequence to the document when “Insert” is clicked. “Insert” would move the focus back to the document, but leave the ISC window on screen, so that the focus can be returned to it for the next insertion.
It doesn’t seem that LO works like this, however.