New window for selected subdomains

I have a number of subdomains, all managed with Drupal: links are marked with the extlink icon, opening in the same window.
I have also a single subdomain (not managed with Drupal...) that should really open in a separate window.
Is there a way of achieving that with the current implementation? If not, would it be a sensible feature request?
Maybe something along the lines of block configuration:
"new window on every (sub)domain except the listed ones"
"new window on only the listed (sub)domains"
Thank you.