How to add a NaN row at the beginning columns of a table?

I have a code that looks like this:

A(:,1)=[NaN;B(1:end-1)];
A(T.id(1:end)~=[NaN;T.id(1:end-1)],1)=NaN;  
 
A(:,2)=[NaN;NaN;B(1:end-2)];
A(T.id(1:end)~=[NaN;NaN;T.id(1:end-2)],2)=NaN;  
 
A(:,3)=[NaN;NaN;NaN;B(1:end-3)];
A(T.id(1:end)~=[NaN;NaN;NaN;T.id(1:end-3)],3)=NaN;  
 
A(:,4)=[NaN;NaN;NaN;NaN;B(1:end-4)];
A(T.id(1:end)~=[NaN;NaN;NaN;NaN;T.id(1:end-4)],4)=NaN;  
 
A(:,5)=[NaN;NaN;NaN;NaN;NaN;B(1:end-5)];
A(T.id(1:end)~=[NaN;NaN;NaN;NaN;NaN;T.id(1:end-5)],5)=NaN;  
 

I want to turn this into a more compact code by adding NaNs to each row sequentially in a loop at each step but I couldn't come up with a code that can do that

Answer 1

[Daniel Pollard]

for jj = 1:5
    A(:,jj) = [NaN([jj 1]); B(1:end-jj)]
    A(T.id(1:end) ~= [NaN([jj 1]); T.id(1:end-jj)], jj) = NaN;
end

I haven't tested it but something like this is what you're after?

[Mia Dier]

Thank you!!