How to set custom user data directory?

Hello,

searching in Google, I have found the startup parameter --user-data-dir and am using this in a batch file to chose a different user data directory location.
However, this only works when I start Comodo using my batch file.
I have Dragon set up as my default browser. If I open an HTML file or a browser link from within an email, I still get thrown back to the default directory, because the system does not use my batch file for opening URLs or documents that use Dragon based on the default program settings.

Is there a better way to set a custom user data location in Windows (8.1) for a user, which will also take effect when Dragon is opened as default browser?

Thank you…