Apache: force ssl redirect works for all cases but one??

Question

we are registered under verisign for mydomain.com, but not www.mydomain.com, so all of my ssl redirects must also remove the www. (if any). so the redirect must go to https://mydomain.com

it currently redirects to that with:

mydomain.com
www.mydomain.com
http://mydomain.com
http://www.mydomain.com

but does not work for:

https://www.mydomain.com

this is very important, because if the user goes there, because we are not registered with the "www.", they get a security page saying that they are going to a site that says they're registered but are not =(

here's my htaccess rewrite:

RewriteCond %{HTTP_HOST} !^(mydomain\.com)?$ [NC,OR]
RewriteCond %{SERVER_PORT} 80 [NC]
RewriteRule ^(.*)$ https://mydomain.com/$1 [R=301,NC,L]

any ideas as to how to extend that to include redirecting if they go to https://www.mydomain.com?

thanks!