I was all this morning making tests.
With the set up you sugested i did not capture any traffic.
Then I made a rule:
10 * ETH00 MARK tcp opt — in * out ETH00 0.0.0.0/0 -> 0.0.0.0/0 MARK set 0x10 OUTVPN1 yes
And then I filtered the log using the IP Address from the remote VPN client (Internet IP) and had no results. As we were talking in another post about qos+proxy, I think the traffic for open VPN is not seen by the QOS clasifier at the Internet interface.
I will continue making tests and, of course, i will post any results i get.
I know that what i am trying here is not easy, but i am sure its a way to make it work.
Thanks for allyour help.