modifying code to insert three columns repeatedly

hello
I got assistance from @nankw83 in this thread
https://www.excelforum.com/excel-pro...ml#post5556215
now I would modifying the code by insert three columns repeatedly when run macro every time should insert columns sale,ret,balance with add different formula as I put the result in sheet new result
the code sum the data based on some headers for all of data across sheets .

if it's not possible to modifiying then I accept new macro