VPN

Is possible (if yes how) setup m0n0wall that users from one side of vpn tunnel can access internet through this tunnel ?

Thanks

Yes.

Fun way to do this #1.  Setup a proxy at the other side of the VpWAN and set the clients at your side to use the proxy.

Fun way to do this #2.  Set a static rout on the m0n0wall to force all traffic not bound for the LAN Subnet to a router on the other side of the VpWAN.

Either will work, but your choice should be designed around your overall goals.  If you want a bit more HA involved, I would use option #2 so you can remove that static route in the event the VPN is dead and the other side cannot be reached.  Thus, your people can still get to the Internet.

If you wish to monitor all traffic, control content, etc. then option #1 is best because you probably do not want people to get around the proxy and do not want them to use the local Internet if the proxy is unavaliable.