I may be misled but I think the quickest way may be to highlight the email list in AppleWorks 6 then copy/paste them into the body of a new email & mail it to yourself.
If your Mail.app recognises them as seperate hyperlink email addresses when you receive it into your inbox, and it should, Ctrl/Right-click each & select from the contextual menu.
From the test I did myself I have the option to "Create a new contact" or "Add to existing contact" but I'm running 10.7.6 so your version of Mail.app on the old eMac will likely be different but it should be feasible.
As for importing under "one group", once you have manually added each address you will need to create the group.
Having said that, if you have a mac at home running an updated version of Mac OS X & you have Pages or a similar word processing app, even a freebie like Bean, you could export the AppleWorks 6 file as a version that Pages or Bean or whatever, can open, then the email addresses might be recognised as hyperlinks & you may speed up the process of adding them to Address Book ...