Train from Samarkand - Khojand / Tajikistan

Hi,

the poezda webpage shows that there is a daily (!) train from Kazakhstan via Nukus to Samarkand and on to Khojand, Nr. 692, leaving Samarkand at 6.47 am, arriving in Khojand (Hujand in Poezda) at about 3 pm.
Can anyone confirm whether this train really exists (eg blackboard at the station?) or has someone even taken it? Seems like a good alternative. And finally it would be good to know how hard it is to buy tickets for this train..

Your help is much appreciated!