Creating Load Balance PCC with two interfaces bridged to balance only the http port 80

I have the following structure, six stores in a wireless network that each one has its own internet router, and before reaching these routers have a bridge in MikroTik, eth0 external structure with stores on the wireless network, eth1 internal network where I have the 6 routers, one for each store. Today it serves as MikroTik for traffic analysis, firewall, and solve network problems. However, I have unbalanced traffic in the routers, most, more than 80% is http (port 80). So I wanted to configure a Load Balance PCC on this computer only to balance the load http. My topology is as follows:


Stores stations (192.168.x.x/24)
01 02 03 04 05 06
1.x 2.x 3.x 4.x 5.x 6.x
| | | | | |
| | | | | |
192.168.x.1
Ubuntu
Dansguardian
Squid (Transparent)
Samba
192.168.10.x
| | | | | |
| | | | | |
Wireless network (192.168.10.x)
01 02 03 04 05 06
x.31 x.32 x.33 x.34 x.35 x.36
| | | | | |
| | | | | |
eth0
Mikrotik Firewall enabled and bridged
| | | | | |
| | | | | |
eth1
Switch
Routers, one for each store (192.168.10.x)
01 02 03 04 05 06
x.1 x.2 x.3 x.4 x.5 x.6
| | | | | |
| | | | | |
INTERNET

I want to balance only the http port 80 and I need a rule for exceptions, which may include addresses by the router to keep the store already use.