How to paste every third row in Excel, please help!

Hi all,

I have just started using Excel and I have a very very basic knowledge of Excel, but I need it for work. I have 8 columns of data that needs to be alternating every third row by subject data, however there is no option under "paste special." I have been googling and I think I might need a "macro" but I am not sure. The values for each cell are unique and do not repeat.

The format should be like this:

1st row =subject A data
2nd row =subject B data
3rd row =subject C data
4th row =subject A data
ect..

For example how it would look in Excel:
A1 A2 A3 A4 A5 A6 A7 A8
B1 B2 B3 B4 B5 B6 B7 B8
C1 C2 C3 C4 C5 C6 C7 C8
a1 a2 a3 a4 a5 a6 a7 a8
ect.. where Letter# would be a numerical number (such as A1= 101, B2 =93, ect)


There are 45 rows for each subject pool, for a total of 135 rows (which should be alternating by subject data) and there are 8 columns.

I would appreciate any help/suggestions! I have never coded before so this is all new to me.
Thank you in advance!