http://wiki.mikrotik.com/wiki/Load_Balancing_over_Multiple_Gateways
i m using this configuration in pptp scenario All works fine !!
but i have a problem !
when i open web proxy in mikrotik it cannot resolve host name.
help me !
it is impossible to redirect traffic to webproxy on a routerboard that is making a load balance
you would try to put another mikrotik for webproxy redirection
would u please give an example !!!
how can i do it ?
reply ???
plzzz reply !!!
yes it’s possible, dont remember how 
but i did it sometime, I check the traffic as local in the prerouting rules maybe with the port of web proxy, but it works i remember it