webproxy and apache issue

i have installed apache on windows xp and the port is 80 by default for all user’s and i want to run it on lan user’s but i am facing a lil problem that is that apache web server only works on my pc not working for lan clients

i am using Mikrotik webProxy + cache and there is a rule in IP/Firewall/NAT which is
1 chain=dstnat protocol=tcp dst-port=80 action=redirect to-ports=3128

please help me here to fix it that my apache work on lan