Got it

I won’t have to “manually do a ‘new contact’ in RoadRunner web-mail for every single entry in my AppleMail address-book.” (There were nearly 100.)
It so happens my old tower, which still works, had an address-list in its Netscape e-mail.
It was the address-list from which my AppleMail address-list was generated.
Fire up old tower. Fire up Netscape address-book. “Export” as .csv (comma-separated).
Fire up RoadRunner web-mail in browser on old machine.
“Import” address-list.
Grab Netscape .csv export from Desktop.
VIOLA! Almost 100 e-mail addresses instantly appear in my RoadRunner web-mail address-list.
I can compose and send e-mails via RoadRunner web-mail when out-of-town.
I.e. I won’t need a Rochester RoadRunner Internet connection to do e-mail. (Out-of-town my AppleMail wouldn’t send.)
There are a few missing that were added only on this laptop (not the tower). But only a few.

• My e-mail is via “AppleMail;” back-and-forth over the Internet.
• Our Internet-connection is Rochester RoadRunner via cable. Out-of-town RoadRunners are firewalled, and won’t take sent AppleMail e-mails.
• I’m age-67 and had a stroke (October 26, 1993). I’m not supposed to be able to do this.