I made a custom Variable that increases through focuses and events. But i don't know if it's actually working. So I wanted to ask if someone know if i can in some way make clear, that this variable works

You could create an event that can only be triggered by the console, and use that variable in the description, or something, if there's no obvious way to see it.

If you're going to do this, you'd add:

[?YOUR_VARIABLE_NAME] where the variable should show, e.g "There are [?swiss_gold_reserves] in the gold reserves"

Then in game, in the console put:

"event YOUR_EVENT.ID" - without quotes (the thing which shows up when hovering over it in the event tool)

And that should say something like:

There are 123 in the gold reserves (or whatever your message says)

ah thx for help ^^