こんなんじゃだめですか?
(すっごい適当に書いてます。)
Open "aaa.txt" For Output As #fileNum
i = 3
Do Until cells(i, 1) = ""
str = cells(i, 1).value & "," & cells(i, 2).value & _
"," & cells(i, 3).value & "," & cells(i, 4).value & _
"," & cells(i, 5).value & "," & cells(i, 6).value & _
"," & cells(i, 7).value & "," & cells(i, 8).value & ","
i = i + 1
str = str & cells(i, 1).value & "," & cells(i, 2).value & _
"," & cells(i, 3).value & "," & cells(i, 4).value & ","
i = i + 1
str = str & cells(i, 1).value & "," & cells(i, 2).value & _
"," & cells(i, 3).value & "," & cells(i, 4).value & ","
i = i + 1
str = str & cells(i, 1).value & "," & cells(i, 2).value
Print fileNum, str
i = i + 2
Loop
Close #fileNum
お礼
sh_hirose様 ありがとうございました。 ポイントはつかめましたので、投稿をベースに加筆しました。