Select every N-th row and replace column values

[ushbar]

Hi,

I'm new to VBA and macro so I need help with a script/code that can select every 18th-21th row and replace column "I" with the following values:

- Paranøtter
- Pekannøtter
- Pistasjnøtter
- Valnøtter

and replace column "L"-"O" to blank (should be no values).

This should be a loop.

I have attached a part of my dataset and highlighted the rows and columns I want to change. I have also attached a picture to better understand why this should be repetitive.