Sort of amazingly enough this code works great to open an ftp directory:

loShell = createobject( "shell.application" )
loSource = loShell.NameSpace( "ftp://1.1.1.1/exports/" )
for each loFile in loSource.Items
   debugout loFile.Name
endfor

Trying this in C# though doesn't:

using System;
using System.IO;
using System.Collections.Generic;
...
DirectoryInfo di = new DirectoryInfo("ftp://1.1.1.1/exports/");

Is there an equivalent in the .Net framework?