I was able to find out on another forum in case anyone was wondering.
"there are 2 files all found in the \windows folder:
et9cdb.cdb - for custom phrases
et9rudb.rdb - for custom words"
I haven't tried backing up and restoring it yet but once I do I'll let everyone know. I also tried searching for XT9 stored entries. The link to the other forum is
http://www.ppcsg.com/index.php?showtopic=96189&st=40