The software for my Sleeptracker watch expects all AM/PM symbols to be "AM" and "PM". However, on my machine, I use "A" and "P", throwing it into a hizzy. How can I apply a compatibility shim to this program so I don't have to go into the Control Panel and change my AM/PM symbols every time I run the program?
Under the assumption that this is a Windows question, you could create a second user account that uses AM/PM, then use Fast user switching to switch to that user account and run this one program.
Fast user switching is on by default, but if it is disabled for some reason, then see this article.