How to insert certificate serial number and ssl verify result to http header both ?

Thanks to Colin and unRuleY.

I have completed my rule based on unRuleY's advice.

when CLIENTSSL_CLIENTCERT {
   set ssl_stuff [list anything1 anything2]
   set ssl_cert [SSL::cert 0]
   set ssl_errstr [X509::verify_cert_error_string [SSL::verify_result]]
   lset ssl_stuff 0 $ssl_cert
   lset ssl_stuff 1 $ssl_errstr
   session add ssl [SSL::sessionid] $ssl_stuff 180
}
when HTTP_REQUEST {
   set ssl_stuff2 [session lookup ssl [SSL::sessionid]]
   set ssl_cert2 [lindex $ssl_stuff2 0]
   set ssl_errstr2 [lindex $ssl_stuff2 1]
   if { $ssl_errstr2 eq "ok" } {
      HTTP::header insert SSLClientCertStatus $ssl_errstr2
      HTTP::header insert SSLClientCertSN [X509::serial_number $ssl_cert2]
   } else {
      HTTP::redirect http://192.168.0.64/error.html
   }
}

I have to change the syntax of "lset" and add "set" before "lset", becuse it didn't work if I wrote like this:

lset my_ssl_stuff {[SSL::cert 0] [X509::verify_cert_error_string [SSL::verify_result]]}
session add ssl [SSL::sessionid] $my_ssl_stuff 180

Thanks again, unRuleY, for your "lset&lindex" advice!