right, that's what I meant by a crutch.
You may need to isolate that particular application, change the settings, run the app, put the settings back.
If that's not feasible then maybe move that application to a dedicated machine.
Your options are - change the code, configure windows or configure the app's regional settings.
If the 1st and 2nd aren't possible/desirable
Then you will have to configure the application itself. If the vendor doesn't allow that then you're stuck, sorry. Have to move to a new app and new vendor that will support you.