So, if you have the RDP file in a common folder that you have access to (\\server\share), then next question would be if you do it as a custom action they can be done as the logged in person or system I think. So, assuming access to the source .RDP file is one thing, but at all the destinations you would need access.
then it would be does everyone have the same or similar OS?
so you could do it with powershell or CMD using copy command or xcopy
copy \\source\remotefile.rdp %PUBLIC%\desktop\remotefile.rdp something like that depending on client OS. I have not tried it so that is off the top of my head.