multi user file access

I would like to control access to a file concurrently from two users. Access in the sense that when winscp after login shows the dirs and files of the remote computer one can double click a file, edit it locally and let winscp upload it back automatically. I want to know if winscp already has a function where it prevents one user from accessing it while another user is editing it.
Thanks in advance,
Ines

While such functionality is supported by SFTP protocol, I'm not aware of any server actually implementing it. So even if it is added to WinSCP it would not work.