Ok, I found it.
I needed two cables called "MHF4 plug to MHF4 female PCB with 0.81mm cable".
Here they are:
http://www.ebay.com/itm/MHF4-MHF-4-plug-right-angle-to-female-PCB-with-0-8mm-Pigtail-Jumper-cable-IPX-3-034-/181810688615
With those cables I was able to extend the antennas and now everything works fine!