If you don't want to get the Xtension mentioned by kc, then just enter your exceptions while no documents are opened. This creates a global hyphenation exceptions. Be warned though that if your Xpress Preference file becomes damage in the future, there is no way to recreate the exceptions from a previous file. You'll have to retype it. This is the problem that I am currently experiencing. I have not found a way to recreate the list. I've email Quark Support and am waiting for a reply.
Just got an email from Support about appending hyphenation exceptions from previous file. This is what I wrote:
"I am aware of the global hyphenation exceptions. However, the previous global Hyphenation Exceptions that I created was lost when the Xpress Preference file was damaged. It seems to me that if I am able to append other preferences from other files, then it should be possible to append hyphenation exceptions. What if my hyphenation exception lists contained hundreds of words (or thousands), am I to retype every one of those words individually if the preference file is damaged? Don't you think that the ability to append hyphenation exceptions should be an available option considering that most users will use the same exception repeatedly, just as other preferences, settings, or styles?"
This is Support's reply:
"If you set up a lot of Hyphenation exceptions, you should keep a backup of your Xpress Preferences file. However, I've forwarded your suggestions to the concerned department."