Is it possible to create some sort of "symbol shortcut" in Word?

Two methods come to mind.
(1) Go to the Insert tab and click on “Symbol”. If the symbol you want is there, just click on it, and it will be inserted into the document. If not, click “More Symbols”, and you can find more symbols, and you can also define Shortcut Keys for that symbol, as in your Shift+s example. Or, what I like to do, is define an Autocorrect for that symbol. For example, I have defined “chm” to insert a check mark in my document. I used chm because I never expect to actually need that sequence of letters in any document, so I instruct Word to “autocorrect” chm into a check mark.
(2) You can record a macro. A macro is a sequence of recorded keystrokes saved and given a name. Then you can associated the macro name to Shortcut keys, or even a button that you can place on the quick access toolbar. You can then invoke the macro by typing the shortcut or clicking the button. Read more about macros in the Help files.

@2davidc8 Thank you. I was doing the first one all the time so far. I’ll try out the macro thing now.

Google “how to create macros in MSword”, then pick the MSword version you have.

@2davidc8 I just made it! Thanks again, you saved me a lot of work.
@Espiritus_Corvus Just did it. Thanks for suggesting.

For the first option suggested by @2davidc8 , you can use Alt+Ctrl in front of a keyboard character for the shortcut, so in your case you could us Alt+Ctrl+S for š. That way, you can write a word in a foreign language by holding down the Ctrl and Alt keys with one hand and typing letters with the other.

I use AutoHotKey (see autohotkey.com) for a free tool with excellent help and loads of features to do all of that and more. It enables me to store all kinds of keystroke shortcuts such as described above … and which are then platform-independent. That is, I don’t have to set up the same “autocorrect” changes in different programs; the same keystrokes in nearly any application will be translated into whatever word or shortcut I have programmed into AutoHotKey.

I also use it to start a number of programs and websites on the fly, so I don’t have to go to a desktop icon or the Start menu; just type Ctrl-Winkey-X at any time, and Excel is starting pronto, for one example.

Great suggestions above. One more that I have used for recurring special symbols or even names that I have to take care to spell correctly throughout (such as Nietzsche) is to give the word its own code—something that can’t occur in normal text, such as %n—and then search and replace it once at the end.

But why do you have to rewrite? Is the source document in longhand? If it exists in electronic form, can’t you capture the keystrokes?

@Jeruba It’s a university project my professor participates in. A lot of old books, from XVIII century, are well kept, but they need to be typed into electronic form for better research. They exist only in physical form and digitalised. It’s the format you’d see in Internet Archive. Basically, it’s images, so I can’t capture the words. The problem with it is that it’s bacially a combination of two alphabets, so I had to make some shortcut and avoid switching between keyboards all the time.

Thankfully, I’ve just finished. Phew.

Thanks again, people.

Œ I don’t know if this will help, since you’re done, but for the future you can find lists of alt codes. You hold the alt key down and type in numbers to get the symbol you want. Here is an example. There are many more out there. ƒ £ Ð.

Sounds like an interesting project @Sneki95.

@Dutchess_III It is, and it’s beneficial too. Makes me feel productive.

Ah—I misunderstood “rewriting.” You were transcribing text from primary source material. That’s a very valuable contribution. What two alphabets were they?

Is linguistics your field of study?

@Jeruba I study philology. Serbistics, to be precise. It’s close to linguistics, but with some minor diffrerences.

The text I was working on was form the XVII century. It’s written in Slaveno-Serbian, the literary language from that era. The alphabet was a mix of Serbian and Russian Cyrillics, with some micro influence of German (for example, nouns were written in big caps).
It’s a collection of folk tales.

Thank you all for the additional tips and tricks!

By the way, most of these tricks work in Excel as well.