Let me try..
TC = C; //todays close
YC=Ref(C,-1); //yesterday's close
Y2C=Ref(C,-2); //day before yesterday's close
//Cond1=TC > YC > Y2C;
Cond1=TC>YC AND YC>Y2C; // Thank you Leenaji
TV=V; //todays volumes
YV=Ref(V,-1); //yesterday's volumes
Y2V=Ref(V,-2); //day before yesterday's volumes
avgV = (TV + YV + Y2V)/3; //average volume for last 3 days
Cond2= avgV > 100000;
Cond3 = C > 50;
Buy = Cond1 AND Cond2 AND Cond3;
Filter = Buy;
AddColumn(Close, "Close");
AddColumn(V, "Volume");
AddColumn(avgV, "AvgVolume");