[otrs] passwords

Greeting, I have setup otrs and its running. I have an inhouse authentication system used that I have integrated into otrs, but I am stumped on one last issue. I would like to use the encrypted system password for a user and use that as the password for otrs also. 1. Where is the salt defined? I see from the db that the first two characters of the username are used as the salt, but where is that configured? 2. Any suggestions on ways to accomplish this? Thank you in advance. Andrew