在第三个文件中写入两个Excel文件的内容

I'm very new to vba programming and I would like to know what is the best method to do the following operation : read data from two Excel files (from a particular column of each file) and write this data in a third Excel file, writing the data contained in the first file first then the data contained in the second file. The figure below illustrates what I want to do : I'm very new to vba programming and I would lik