hang-the-9 :
You may want to talk to the people that gave you the IP address, just the IP address does nothing for anyone without something to do with it.
It's like giving someone the location of a door without telling them where the lock is.
More like the location of a door, but not the instructions of how to open it.
Here at our place of Biz we have multiple ways to access company resources remotely. One way is to RDP (mstsc.exe - MS Terminal Services Client/Remote Desktop Protocol) to a specific IP address and our Remote Access Server fields your request and allows you to login. Another method is VPN as stated before. Other methods could be Exchange access via Outlook Web Mail.
As stated, an IP is only one piece of a larger mechanism, but without knowing what the whole machine looks like, you are just holding a cog!
Hope that elaborates a little more too.