little help with a rule

Hello there, i have a mikrotik server which has 2 NIC one is for my lan and one is the internet conection from my isp, but my isp has disable the internet without proxy by so there is no internet without proxy in my lan, what should i do to enable the internet without proxy to my users? thank in advanced.

maybe transparent proxy works?
http://www.mikrotik.com/docs/ros/2.9/ip/webproxy.content#7.53.7

just redirect it to your real proxy