Public IP routing and Squid Tproxy

I am using mikrotik as pppoe server and provide public ip (Routed Pool) to users.
Mikrotik WAN IP = 1.1.1.2/30
Users Pool = 2.2.2.0/24

Now I wan to add SQUID as TPROXY (So that users real ip should preserve).
How can I connect squid box? how many interface would i be requiring in the squid box? should squid box also have public ip ? or how? please guide,