You should try post this relevantdevelopers groups as well.
Anyway - this is one of article I found over the years.
How To Write Pluggable Protocol to Support FTP in Managed Classes by Using
Visual C# .NET
http://support.microsoft.com/Default.aspx?id=812409

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Regards,
Bernard Cheah
http://www.iis.net/
http://msmvps.com/blogs/bernard/
> Hello
>
[quoted text clipped - 3 lines]
>
> Thanks for help and hints!