If there is a SharpDevelop way of doing thisI haven't tried it with that specific example, but for more common reference cases it's simply
"C:\Program Files\Mono-2.4.2.3\bin\gmcs" prog.cs /r:Interop.IWshRuntimeLibrary.dll
(where Interop.IWshRuntimeLibrary.dll is in current directory), then I haven't been able to find out what it is.
-reference:System.Windows.Forms
or whatever