getting gcc-java-4.6.2.tar to work on 64 bit Windows 7 MINGW32

I have the libiconv binary and developer files successfully downloaded and 
referenced inside
MINGW32 from 

/etc/profile

export PATH="/home/User/thisiscool-gcc/gcc-ecj/bin":$PATH;
export PATH="/home/User/libiconv-bin":$PATH;
export PATH="/home/User/libiconv-lib":$PATH;
export PATH="/home/User/nano":$PATH;

I have got the source code for

gcc-java-4.6.2.tar

sitting there ready to compile and build.

What do I need to do from here, so that gcj can generate (compile)

.class files?
win32 executables?
.jar files?