merge excel files column - easy task automated

Hi, I got 4 excel sheet of around 1500 lines each. they are all duplicated, i need to merge 2 columns. it's an easy task. For example, the tablesheet from group A, have around 400 lines. the same tablesheet from group B, have around 600 lines. it's the same tablesheet, except the B have more lines, and 2 column that i need to have in tablesheet from group A. I need you to give me back the tablesheet from group A , but you add the column E and F to them (that you will compare with the same tablesheet from group A