"Pin" row to imported range in sheets

Hi experts,

I am importing another dataset from a different google sheet and I am wanting to add a "Notes" column to people can provide updates which is an addendum to the import. Because the number of rows changes constantly (everytime the other sheet updates) the "Notes" row no longer matches the earlier version. For example:

Day 1:
Account | Product | Notes
ABC | 123 | ABC really love using 123
DEF | 345 | DEF are having issues
GHI | 678 | GHI want to move to product 345

Day 2:
Account | Product | Notes
ABC | 123 | ABC really love using 123
GHI | 678 | DEF are having issues
JKL | 911 | GHI want to move to product 345

Is there a way to keep the notes column "pinned" or always synced to the original row somehow?

Thanks in advance.