Fantastic, just what I needed.

Thank you,

Sorry, we do not have an offline documentation. Only the online one. Also there's no special documentation for COM. It's same as the .NET.
The numerical values are not documented. It should not be needed. If you need them anyway for some reason, please see the source code:
https://github.com/winscp/winscp/blob/master/dotnet/SessionOptions.cs

Is there a CHM file or PDF documentation for the COM library. I see plenty for .NET. Where can I find the values of the manifest constants like Protocol_Sftp, is it numeric, what is it's value. I'm using C++.

Thanks,