Getting client ip address with apache front end and tomcat back end

Hi all,

I had the following code in my httpd.conf which does not work. When I
google it, I found somebody else has exact same problem. I am wondering
if any one know any other way to do it...

RewriteEngine on
RewriteLog "/tmp/rewrite.log"
RewriteLogLevel 9
RewriteRule ^(.*)&(.*)$ $1&$2 [S=1]
RewriteRule (.*) $1&%{HTTP_COOKIE}
# If there's a '; ' then there is more than one variable left
RewriteRule ^(.*);.(.*)=(.*)$ $1 [E=$2:$3,N]
# Now there's only one variable left
RewriteRule ^(.*)&(.*)=(.*)$ $1 [E=$2:$3]
RewriteRule ^(.*)&$ $1
RewriteRule ^/(.*)$ /done$1 [R]

RequestHeader set sm_user "%{smuser}e" env=smuser
RequestHeader set add goHierId %{goHierId}e env=goHierId
RequestHeader set sessionid %{sessionid}e env=sessionid

When I look at the request header, I don't see the value, it was set to
null. Do anyone know why and how to fix the problem?

thanks in advance