File associations: command line options?

Currently, the file type associations in the Preferences is quite dumb. I can't add more associations, nor I can't edit the command line options.

I have a problem with Corel Draw, double clicking .cdr files always opens a new instance of Corel. This may be prevented by a command line options, however, I'm unable to edit that.

Is there a config file where the file associations may be edited in Notepad++ ?