I designed a feature like this when I worked on HP's email archiving product for Notes & Domino somewhere around 8 years ago.  It did not require the Notes C API.  It was an ordinary agent that did the work. Our agent was written in Java, not Lotusscript, but this part easily could have been LotusScript. 

We did it by creating a configuration document containing a rich text field, where the rich text field contained a hotspot that already contained the formula that computed the URL.  The formula referenced items that our agent would add to the (mail) document in order to build the specific URL that pointed to the archived version of the document in our (non-Notes/Domino) storage system. The agent simply used the NotesRichTextItem.AppendRTItem() method to copy that prototype rich text into the mail message's rich text.  We used Append because we (optionally) left the first few lines of the original email message in there. It would work just fine if we stripped the original message text entirely, and we did support that option, too.

If I recall correctly, we used hide-whens to activate different links for Notes client and browser users. I think it was a computed hotspot link for the Notes client and computed text marked as pass-thru HTML for the browser users, but I won't swear to that. I also recall that we had to deal with some sort of workaround for a security feature in DWA that blocked "active content", making our links for browser users fail.  There was, if I recall, a notes.ini setting to disable that.

Hope this helps.   

Hello Rob,

That sounds like a good work around for the same issue but for my problem the environment variable is stored in each user's mailbox database for the server they need to connect to and this can change.  So I need the email message bodies in their mailbox databases to have the URL link with the computed formula.  This way every time they click the link it recomputes the correct link before making the connection to the correct address.  This will allow it to continue working if the address changes.

I appreciate the idea and might be something to consider using in the future if a slightly different scenario.

Thank you,

Larry