Save list of rows as .txt based on their index in column A

Hey,

I'm having an hard time trying to split a .txt file into several different .txt files with the same layout based on the value in column A. I have 4 columns with sequential values divided by row, in column A there's is the index of rows belonging to the same family from 1 to n (length of this column and of each family could be variable from file to file). Now I would like to save the list of rows by family, each in a new .txt file called Family 1, with also an additional row in A1 cell stating the family name (e.g. "Familiy: 1")

I wish to have this files saved in the same folder from where I read the original file.

Could someone help me with this?

thanks