Hi Hawkeye,
sorry I have to disappoint you: There isn't even an internal key for this. The data-folder must be a sub-folder from SiDiary's base folder. If you want to switch your data to the other partition, you have to move sidiary.exe also. But since everything that is needed for SiDiary is located in this folder you're definitely done after moving the whole folder - there are no registry settings or something like this.
Just the shortcuts from within the program group have to be actualized but you can wait with this step because the 4.0 release version will allow also to update this shortcuts from the more settings screen (good timing - I've added this button yesterday night!
).
But I will put a data-folder setting key like to my ToDo-List...
Bye, Alf.