I find it most convenient to use tsclient.

First, enable Drive Redirection.

  1. Right click on the RDP file.
  2. Go to the Local Resource Tab.
  3. Click More....
  4. Choose Drive > OS (C:)


Next, Connect to the remote server and use the tsclient e.g., like this:

$ xcopy C:\tmp\my-large-file.csv \\tsclient\C\dev

See https://support.microsoft.com/en-us/topic/3eeb41aa-2200-4b8f-95d1-f5f7ab2122c4