result = zeros(1, 100); % Pre-allocation
for k = 1:100
result(k) = rand; % your value
end
Or maybe you mean:
index = 1:6:100;
result = zeros(1, numel(index)); % Pre-allocation
for k = 1:100
match = (k == index);
if any(match)
result(match) = rand; % "logical indexing"
end
end
