With more modifications, it might be possible to build remctl against SSPI, the GSS-API-like interface built into Windows, and remove the dependency on MIT Kerberos for Windows. However, limitations surrounding realm trusts in the Kerberos implementation in versions of Windows prior to Vista would make this a less general solution.
A probably better approach would be to write a separate client implementation of the protocol in .NET (C# or C++ depending on what APIs are required).