I'm not sure I fully understand your question - but this might prove useful:
You can use setup MOSS lists to receive incoming mail and then send a meeting invite to that email address. Create a calendar list, and in the list settings select 'Incoming e-mail settings' (If you haven't set this up on your MOSS farm, you can Google how to do so)
Allow your list to receive email by checking the box and give your list a suitable email alias. Allow your list tor receive attachments and accept mail from any sender (you could dive into permission-based senders if you want, but outside scope of this).
Now whenever you setup a meeting just include the email alias you used for the list as a meeting request recipient. The list will receive the email and include the meeting on your calendar with the appropriate details.
You can then overlay this shared calendar in your outlook if you select 'Actions' - 'Connect to Outlook' from the calendar list.
May have misread your intention here - so sorry if the above is not relevant.