Load this, then do a Select All and a copy. Open up Eudora, and go to the Nicknames screen. To create a new nickname, hit "New". Call the nickname "gss." Then go into the addresses field and "Paste." Save the changes to the nicknames. Then, whenever you want to send a message to us all, in the To: field just type "gss."
If you already have a Eudora nickname, simply load the update, do a Select all and Copy it. Go into Eudora. Open up the Nicknames window. Find and select your gss nickname. Go into the address screen, do a Select all and then a Paste. Your mailing list will then be updated to the most recent copy here.