Running 16-bit apps from within a Java p

I am on WindowsNT using JDK1.1.8. Using the Runtime class of java, I can successfully invoke 32-bit GUI apps such as Notepad. But when I try to invoke 16-bit or command line 32-bit apps, either nothing happens or some error occurs. Why? What’s the correct set of steps or method?
I am using this method to call on an external compression program to zip-sfx certain files. Any other way to do this without invoking an external file?