Hello and welcome to the forum,
You may want to consider a delimiter other than comma as comma is often found in the data (personally i use the pipe or the tilde).
On the mainframe suggest you pre-allocate the target PS file with enough space to hold the upload.
Your desktop tcp/ip software will most likely have an ftp client (rather than being configured as an ftp server). It can be Win-based or run from the command prompt.
Good luck and someone will be here if there are questions/problems.
Hope this helps,