I'm contributing my XML code to give you some ideas and starting point and as a big thanks to all who are giving answers to the forum questions. I used it a lot and my code has about 1200 lines right now. The string operation might not be perfect same with selection of interim variable names.
We're only using en-US operating system globally, but the code can be easily extended.
As already mentioned in other posts by Jason it is not possible to react dynamically on keyboard layout when e.g. changing the time and currency as it is all within the same input dialog. But I can live with the limitation as I didn't want to split it across several input dialogs.
I added a final dialog which will show the values for the OSD variables so you can proof if my values and string operations are correct and makes sense to you.