Tomcat session cookie configuration

Hello,

I want to use Tomcat 5 into the following architecture :

Apache 2 (host A)-----> Tomcat 5 (host B)

Apache 2 has rewrite rules :
Client URL : https://www.my_site.org/my_internet_url/my_jsp.jsp (host
A)
Real URL : http://tomcat_host:8080/WebApp/my_jsp.jsp (host B)

I want to use secure session cookie, with the path /my_internet_url,
but Tomcat put the path /WebApp (cf WebApp.xml) and set no secure for
the cookie (because the scheme of the request before Tomcat is http).

I have read source code from
org.apache.coyote.tomcat5.CoyoteRequest.configureSessionCookie, and I
see that this operation is correct.

How can I do to set my own session cookie path and my own security ?

WebApp.xml
<Context docBase="/home/seb/java/WebApp" path="/WebApp"
reloadable="true" />

server.xml
<Context path="/WebApp" reloadable="true"
docBase="/home/seb/java/WebApp" workDir="/home/seb/java/WebApp/work"
/>