Extern. ip (or forw. port) to MiTk in LAN after router (NAT)

There is a situatin: I have router on LINUX and a few MK(2.9.6) in LAN. I have pool of IP’s that was assigned to interface eth0 (WAN). I want to make forward external port (or write ext. ip to my MT) and conect from Internet to MT via WINBOX (not ssh or telnet). What shoud i do? Any idea?