Yes there is – in this case, select one language you are not going to use; e.g.
It does not really matter whether the ISO code matches and/or name match your actual language – just make sure that whenever you show the language value somewhere, or for example use the ISO code in an api, that you use the correct alternative for your own language. In that sense, the selected language is just a key – valueList ; so you can use any language ISO you will not use, and fill it out for your language.
Here is an example of a language switch snippet: it horizontally lists the icons for each language available in the system. As you can see, we are not using the attributes of the System.Language Entity for communication to the user, but using our own images + hover message conditionally. For your language, just add your own desired image, and edit the condition to the ISO you have selected for use.
Hope this helps; if it did, then please mark as correct ;-)