Well, I tried both suggestions.  I first tried the filter and it still made a 
local link out of it, i.e., not leaving the external link alone like it does 
with the other external links on the site.

I then complied the RC and then tried again, and it still makes a local 
link out of it as well - even when enabling the above mentioned filter.

As a note, when applying the filter (in both 3.23.20 and the recent RC) it 
makes a link of:

<https://www.mysite.com//www.externaldomain.com/path/to/link.asp>

Here is the command I'm using:

httrack -%q0 -L0 -N102 --cookies=0 --user-agent 'V2WebCrawl' -C0 
--do-not-log --quiet -I0 '-https://*' --mirror <http://www.mysite.com/>
'