Passing SSL traffic through corporate proxy using nginx - ssl

Question

I have done some resarch for this matter and there are some unaswered question regarding my issue, however I managed to solve half of what is needed (thanks to people on the site).
Scenerio:
I have Nginx as a reverse proxy in internal corporate network. I need to pass traffic to Internet behind corporate proxy.
Half of the solution:
To achive this, following works fine:
server {
listen 80;
server_name myhost.com;
location / {
proxy_set_header Host google.com;
proxy_pass http://corporateproxy:9999/;
}
}
However, above solution does not use SSL between corporate proxy and google.com. Do you have any idea how to add SSL to this?
I have tried adding protocol or port to header but it is not working this way.
I cannot modify anything on the corporate proxy. It should work like this: the URL being accessed is with https it will be redirected to https; http to http. Unfortunatelly header that contains only dns name is treated as http request.
Unfortunatelly the simplest solution does not work because nginx does not respect http_proxy settings on RedHat Machine:
server {
listen 80;
server_name myhost.com;
location / {
proxy_pass https://google.com/;
}
}
Any help will be highly appreciated.