a) Yes, an .exe or .xlsc file compiled with XLS Padlock can certainly reference and save output files to a OneDrive path. The exact path on OneDrive would be treated like any other directory on your system, so as long as you have the correct permissions set up, you can save files there.
b) As for running .exe files directly from OneDrive, it is technically possible, but it’s not generally recommended due to potential conflicts with OneDrive’s syncing processes. Some users have reported issues where OneDrive detects changes in the .exe file as it runs and attempts to sync those changes, which can interfere with the operation of the program. It is generally safer to run the .exe file locally and let OneDrive handle the syncing of data files only.
If you want to distribute your application to others via OneDrive, a better method might be to zip the .exe file and share the zipped file instead. Your users can then download the zip, extract the .exe, and run it locally.