mod_ssl : %{LA-U:ENV:SSL_CLIENT_S_DN_L} doesn't work

Hi

I need to extrac SSL_CLIENT_S_DN_L from apache (after successful client authentication using certificates)
and pass it to my web application via URL, like :

<a style='text-decoration: underline;' href="https://localhost/ren" target="_blank">https://localhost/ren</a> ... /?SSL_CLIENT_S_DN_L=SomeLocation/


I'm trying to achieve this by using mod_rewrite like that :

....
<VirtualHost _default_:443>
....
  SSLEngine on
  SSLOptions +StdEnvVars
  SSLVerifyClient require
  SSLVerifyDepth 1

  CustomLog logs/ssl_request.log \
  "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x%{SSL_CLIENT_S_DN}x \"%r\" %b"

  SSLCertificateFile conf\ssl\oracle\ssl.crt\server.crt
  SSLCertificateKeyFile conf\ssl\oracle\ssl.key\server.key
  SSLCACertificateFile conf\ssl\oracle\ssl.crt\demoCAcert.crt

  RewriteEngine on
  Options +FollowSymlinks

  RewriteRule rrcp <a style='text-decoration: underline;' href="https://%" target="_blank">https://%</a>{SERVER_NAME}/ren/?CN=%{LA-U:ENV:SSL_CLIENT_S_DN_L}/
....
</VirtualHost>
....

I've never used mod_rewrite before, but according to what i've found on the web i should work, but it doesn't, and what I get
in URL is :

<a style='text-decoration: underline;' href="https://localhost/ren/" target="_blank">https://localhost/ren/</a> .... /SSL_CLIENT_S_DN_L=/

rewrite log shows :

  ...
  lookahead: path=/rrcp var=ENV:SSL_CLIENT_S_DN_L -> val=
  ...

while all apache environment variables regarding ssl are set corretly (i've checked in logs and through phpinfo()).

Can anyone help me to find out what i am doing wrong?

Apache version is 2.0.50, mod_ssl version is 2.0.52, both server and client use certificates and a i'm a newbie as far as
mod_rewrite and mod_ssl are concerned.

Shym
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