acell = num2cell(a);
T(acell{:})
There are also ways to calculate the location as a linear index based upon size(T)
Ts = size(T):
La = length(a);
Ts(end+1:La) = 1;
idx = a(1) + sum((a(2:end)-1) .* cumprod(Ts(1:La-1)))
T(idx)
... if I didn't miss something.
