With your help, I have discovered I can do what I need to using MarcEdit.
MarcEdit is native to the Windows environment, which is what I am using.
Interestingly, it sits on Yaz, which sits on z39.50. MarcEdit has an API that
can be addressed by VBscript or .NET. I have downloaded the client and run
MarcEdit functions using VBscript. It remains to be seen if I can do everything
I want with the MarcEdit API, but it look promising. Thanks to Terry Reese
(MarcEdit) and Index Data (Yaz) and thanks for code4lib input.