Tupolev's, Antonovs, C-17's etc................

Hi guys,I got a question, why can't you select a Tupolev or a Antonov in the drop down menu when you file a flightplan in Squawkbox?The most uncommon and rare planes in the world are listed.........but one of the oldest manufacturers of the world the Tupolev company and Antonov aren't listed????? :-eekWhen I fly the russians I always pick a similiar plane like for a TU-134 a MD80, and put in the remark //TU-134A!!Anyone a solution?:-waveEvert