I need a small program to work within or even outside a word processor that permits me to save in one place individual characters from different fonts. I use quite a number of symbols not all of which are represented in any one font. I don't mind mixing fonts. However, it's really a pain to always have to search through large font sets.

So I'd like to be able to collect, from different fonts, all the characters I need in one place, from which I can easily access them. Does anyone know whether such a thing exists? And, of course, if so, where?

At the moment I'm using LibreOffice on Windows 10, but I wouldn't object to using another word processor if it had this particular functionality. I'm guessing that this would be an add-on or extension to some existing word processor, but I don't really know.

Any help would be much appreciated.