HowTo redirect HTTP to HTTPS on the same httpd?
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
You can use mod_alias and Redirect based on directory. The linked document identifies additional details.
<Directory /path/to/site>
Redirect /service https://foo2.example.com/service
</Directory>