Apache HSTS exception for some virtual hosts

In the global config section for Apache 2.2.15, I have the following (per recommendation)

<IfModule mod_headers.c>
Header add Strict-Transport-Security "max-age=15768000;includeSubDomains" env=HTTPS
</IfModule>

I would like to add this header only when the request is NOT for a specific host (dev.host.com). Which directive do I use to make header add occur only when not for a specific host?

PS: The second part of this question has been moved.

1. If you only include the IfModule directive in a VirtualHost Directive for x.x.x.x:443, then it will only apply to that VirtualHost, and there only apply to the https protocol.

2. You could try the directive

   <If "%{HTTP_HOST} = 'www.dev.domain.com'">
       <IfModule mod_headers.c>
           Header unset Strict-Transport-Security
           Header always set Strict-Transport-Security "max-age=0;includeSubDomains"
       </IfModule>
   </If>
   

In Apache 2.2 you can probably play with something like bellow.

• Set an env to identify general case and exclude specific case:

  SetEnvIf HTTPS do_work_on_headers    
  SetEnvIf Host "^www.myexcludedhostname.tld$" !do_work_on_headers
  

• then conditionnally set headers:

  <IfModule mod_headers.c>
      Header add Strict-Transport-Security "max-age=15768000;includeSubDomains" env=do_work_on_headers
  </IfModule>