R on windows uses a Unix (/) rather than a MS-DOS () slash which makes copying paths etc a problem.
I have a quick and dirty solution that uses a simple dos program to do the conversion and then put the result on the clipboard.
The only minor annoyance with this approach is that it momentarily flashes a dos box up while the app executes but it seems a
small price to pay to avoid messing about with com and shell extensions.
To Use Create a registry entry in [HKEY_LOCAL_MACHINE\SOFTWARE\Classes*\shell\Copy Path Unix Format] and also in [HKEY_LOCAL_MACHINE\SOFTWARE\Classes*\shell\Copy Path Unix Format\Command] @="PUT_PATH_HERE\UnixDirectoryFormatting.exe "%1""
After this Your Registry tree Will look like this SOFTWARE |->Classes |->* |->shell |->Copy Path Unix Format |-> Command
and in command you will have a single key (Default) of type REG_SZ with data ?:...\UnixDirectoryFormatting.exe "%1"
Now if you right click any file in windows explorer you will see the Copy Path Unix Format menu.