Answered in the duplicate post above!  :)

Actually, I want the exact opposite !

I need to call PowerBuilder code from a Java program.

That would be pretty much the same answer. You would call the EXE from the RUN command:

public void excCommand(String new_dir){
    Runtime rt = Runtime.getRuntime();
    try {
        rt.exec(new String[]{"cmd.exe","/c","start"});

    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

Pass in any parameters you need to, as well. 

And of course you can  pass in a string variable instead of hardcoding the

"cmd.exe".

Good Luck,
Olan