FTP Principles with IRC5

In the past, I have programmed a robot that was acting as a slave to a PLC/HMI system with a DNC server for offline program storage. When the operator pushed a button on an HMI, that signaled the DNC to push a module to the IRC5 controller. The PLC then sent a signal to the robot that basically was a trigger to find a file in a specific location on the hard drive, open it, read the header information, and wait for confirmation from the operator that this was indeed the correct program. While it received the FTP'd file, it did not initiate the transfer, it was just a dumb "here you go, open this and tell me what it is"

However, this time, the robot will initiate an FTP request of a file from the FTP server directly, using a name (string) that is variable, which gets set by the operator on the HMI. This information comes by way of his/her selection on the HMI, which tied to the OPC Server and writes to a RAPID string variable. I need to then take that variable string, and somehow basically say "Send me file (strProgramName+".mod"), and then I do the same thing as before where I open it, read the header information, and wait for operator confirmation. I'm not necessarily concerned with error handling right now, I want to get the structure set.

I am sure that this is possible, I have both PC Interface and FTP/NFS client options. Are all the "Socketxxx" instructions what I would do to create this? Create a connection, then "listen" for whatever, and so on? I don't have the FTP Server available (nor am I even sure what server it is), but I want to get it set up (we're a machine builder, so this is typical while the system is being commissioned) for when the system is installed. 

Can anyone give me some pointers and maybe some simple syntax? I've done a lot of things, but this is a first for me (on an ABB anyway) and I don't really know anyone else who's experience i can draw off of who has done something similar. Except for everyone here of course

Thanks!

-Brian