If you just want to move the datasets, the easiest thing is to use the FTP tool that is on your servers. If you want to manage that from SAS, you can just use the "X" command to shell out for execution.
See "Using FTP to Transfer Files in Foreign Format and Transport Files across the Network" in the SAS 9.1.3 online documentation for an example. If you are working from machineC, you may need to first FTP the files to from A to C and then from C to B (depending on your rights on A or B).
Doc Muhlbaier
Duke