Follow this guide for RemoteApp Setup

From your router you will need to enable the Port, and point it to the POS Computer.

You will need to set your Computer to have a static IP Address. (locally). The easiest way is to set the IP address of the TCPIP Verion 4.

Then from your router you will need to setup NAT, to point to 3389, and 3890 ports pointing to the IP Address of the computer.

One you have done this, you can remotely connect using your outside IP address, and connect to the Computer you have designated for remote connection.

If you do not have a POS from us, you would need to setup your computer to allow remote access: http://geekswithblogs.net/twickers/archive/2009/12/18/137048.aspx