I want to write six different values of I, into excel in column and I would obtain another six and write in the column after the last. the code I have below writes everything in a single column

I1 = 1:6; I2 = 7:12; I3 = 13:18; D = [I1 I2 I3]; Count = 0; if ~(exist('input')) =2 xlswrite('input.xls','sheet1'); [raw,~,~] = xlsread ('input.xls'); count = size(raw,1); xlswrite('input.xls',D,'sheet1',sprintf ('%d',count+1)); What code can make it to move in columns