What is the alternate to eval function in a forloop?

EC = [0.0052 0.0104 0.0156 0.0234];
Reff =[4 8 12 16 20]
for i=1:length(FOV)
    f(i)=figure(i);
    hold on
    for j = 1:length(EC)
        for k = 1:length(Reff)
            filename1 = ['FOV_',num2str(FOV(i)),'mrad\',num2str(EC(j)),'\',num2str(Reff(k)),'um\out_resultsG_I0.dat'];
            eval(['I',num2str(i),num2str(j),num2str(k),'=','getsiganl(filename1)',';']);
            eval(['II',num2str(i),num2str(j),num2str(k),'=','smooth(sum(I',num2str(i),num2str(j),num2str(k),',2)',');']);

I have two folders in the directory in which I have the same data files.I am accessing the data at once. The path of the file is \FOV_1mrad\0.0052\4um\out_resultsG_I0 and \FOV_2mrad\0.0052\4um\out_resultsG_I0. The data file I have accessed by filename1=[......]. In the eval function,I is the variable inside the data file (out_resultsG_I0.dat) and getsignal is the file name in the directory. I'd like to avoid using eval function and to use the load function instead to acess the file and load the variable but I'm unable to do so for three loop indices. I need some help to write these three expressions in load function form applying the three loop indices.

Answer 1

[Xingwang Yong]

Using cell array should help

for i
    for j 
        for k 
            I{i,j,k}=getsiganl(filename1);
            II{i,j,k}=smooth(sum(I{i,j,k},2));
        end
    end
end