I have a Java program and I need to acess it from Excel VBA. The way I want to do it is encapsulating the java to a DLL so then I can call it from VBA.
For one of my project, I have use IKVM : http://sourceforge.net/projects/ikvm/
IKVM.NET is a JVM for the Microsoft .NET Framework and Mono. It can both dynamically run Java classes and can be used to convert Java jars into .NET assemblies. It also includes a port of the OpenJDK class libraries to .NET.
And this thread to help you to use it with Excel VBA : http://sourceforge.net/p/ikvm/mailman/message/32106884/ Perhaps, this can help you.