I presume no one worked out how to make this situation work?
I m posting my simple setting of my network, may be its not what u need, but if some one needs to provide internet to LAN with squid 2.6 transparent proxy enable ,
squid box/gateway(192.168.1.1/29) conntected to mt External network adapter ,
LAN conntected to another adapter (10.0.0.1/21)
enabling routing dst=0.0.0.0 gateway = 192.168.1.1
then just have to add Src-nat with masqurading ( ip/firewall/nat
Thats all u need to use both squid and mikrotik , with routing