concatenate multiple variables from multiple .mat files

Hello All,

I need a help in concatenate multiple variables from multiple .mat files stored in multiple folders.

Below is my code, I am not able to get forward with the logic.

clear all
close all
d = uigetdir();
S = dir(fullfile(d,'*'));
N = setdiff({S([S.isdir]).name},{'.','..'}); 
inputfile=fullfile(d, 'input.xlsx');
input_file=dir(inputfile);
read_inputs=readtable([d '\' input_file.name]);
parameter_list={'Var_1','Var_2','Var_3'}; 

for ii = 1:numel(N)
    T =dir(fullfile(d,N{ii},'*.mat')); 
    T([T.isdir]) = [];
    fprintf('Now Reading Folder %s\n',d,N{ii});
    for jj = 1:numel(T)
        F = fullfile(d,N{ii},T(jj).name);
        fprintf('Now Reading file %s\n',F);
            for kk = 1:numel(parameter_list)
                Parameter_name=char(parameter_list(kk));
                x=load(F);
                if isfield(x,Parameter_name)
                    fprintf('Found paramter=%s\n',Parameter_name);
                    parameter(:,kk).data = (x.(char(Parameter_name)));                                    
                end
          Conc_paramter(:,jj).data=vertcat(parameter.data);
            end
    end
              
end

What I want is a final .mat file where all the parameters are concatenated with parameter names.