Finally managed to install the antenna switch in the attic. For controlling it remotely, I use an old Arduino with Ethernet shield. Since the antenna switch needs 12V for triggering its relais, a 4 channel relais module is needed to convert the high signal from 5v to 12v. The Arduino takes simple HTTP GET requests for choosing the desired antenna. Now I can switch to any antenna from the shack via the network without a dedicated control cable 
@DL6MHC Very very nice indeed!