NAT HTTP proxy transparent client problem

[youssef24eg]

Dear all i have problem in the following scenario

i have  a pfsense with 1 LAN and 1 WAN "with 2 internal subnets"  my requirements is
the first subnet to be NAT on an ip and the second subnet to be NAT on another IP
i already did this ,but when i try to use the squid http proxy configured as transparent proxy
pfsense ignore the source of traffic and forward the traffic as it originating from itself
and all the web traffic on port 80 was NAT to a single IP .

so i need that the transparent proxy  NAT  every subnet on different IP

so how can i do this ?