ryuma,
please don't take it the wrong way, but from your posts, it clearly shows that you did not put a lot of effort into researching how EIB/KNX work. This is not a LinuxMCE issue, but a KNX/EIB issue.
To control KNX/EIB you need a gateway, which translates stuff into KNX/EIB. There are interfaces which connect the KNX network to "something" else, like a TCP/IP network or the USB port. Examples can be found on this page
http://mdtautomation.de/KNX.html - Whether or not the USB interface works, I don't know. The TCP/IP interface probably works. I have one, and will give it a test shortly. To check whether or not it works, you need to get in contact with the eibd guys.
Do a google search for eibd and compatibility, and I am sure you will get lots of helpful information.