How can I copy a resource file in a packaged / compiled app?

I have written an app using AppDesigner and I can't seem to figure out how to save my file using a template I created and placed in the resource folder in my packaged app.

The Error I continue to get is 'No Matching files were found.'

            filename_template = 'DesignData_template.xlsx';
            [file,path] = uiputfile(sprintf('DesignData, Panel %.0f.xlsx',i));
            filename = fullfile(path,file);            
           copyfile(filename_template, filename, 'f');