VCN client throught company NAT and firewall/proxy

[Virág István]

Hello All!

I am not good at networking. I would like to ask best
network guru's how to achieve my remote computer
by VNC and terminal server client from company client
throught NAT firewall.

I am working in big company, and another place i have
winNT terminal server. In the company, on the client machine
i can use WWW, msn messenger and yahoo messenger.
I cannot connect by terminal server client or VNC.
I cannot connect with ssh client (putty). In MSN messenger
not proxy settings, in IE i connot see proxy setting because of
no rights.

if i type "netstat -n" on local machine, i got this:

  Proto  Local Address          Foreign Address        State
  TCP    10.131.155.210:1055    10.48.12.12:402        ESTABLISHED
  TCP    10.131.155.210:2828    10.131.152.112:445     ESTABLISHED
  TCP    10.131.155.210:2839    10.131.8.115:389       CLOSE_WAIT
  TCP    10.131.155.210:2880    10.48.12.229:80        ESTABLISHED
  TCP    10.131.155.210:2886    10.48.12.229:80        ESTABLISHED
  TCP    10.131.155.210:2926     x.y.z.c:80     ESTABLISHED
  TCP    10.131.155.210:2948     x.y.z.c:80     ESTABLISHED
  TCP    10.131.155.210:2999    10.131.8.115:445       TIME_WAIT
  TCP    10.131.155.210:3005    10.48.8.204:80         ESTABLISHED
  TCP    10.131.155.210:3012    x.y.z.c:80     ESTABLISHED

x.y.z.c  is   IP address something NAT system or firewall/proxy
i do not know exactly

How can i connect throught to the outside computer by
VNC and terminal server client. I can set up any computer outside
as port tunneling/forwarding, and can run any software local machine
as port forwarder or tunneling. But i do not know what is the
best software, and how to configure exactly.
I do not know how to check connection possibilities.


Thank you help in advance
Stephen