Accessing computer on another domain

I have a huge and urgent problem. I am trying to access a computer on another network but I am not sure I know how or if I did I am coming up blank.
Here is the problem.

I have to install software from a server located on network xx.xx.0.xx. Theserver on which I am installing the software is on network xx.xx.3.xx. I remote connected to the server on xx.xx.3.xx with no problem. I am totally lost but need to get this installation completed today.

Does anyone have a suggestion as to how I go go about gaining access (providing of course I have the correct permissions). I am not sure of the permissions I have to these resources.